Vitamin Information Center

VITAMIN D: “The Sun Vitamin”

Nicholas H.E. Mezitis MD and Despina Komninou MD, PhD, CNS

Did you know that vitamin D, as a hormone, has an important role in metabolic harmony?

Recent studies have shown that vitamin D in its active form is vital for bone health, since it ensures dietary calcium absorption, and helps prevent heart disease, cancer (breast, prostate, lung and colon ), as well as many other illnesses such as diabetes mellitus, rheumatoid arthritis, psoriasis, multiple sclerosis and tuberculosis.

Vitamin D regulates the calcium and phosphorus levels in the blood by promoting their absorption from food in the intestinal tract and by limiting the excretion of calcium by the kidneys. It influences the cells involved in remodeling bone (osteoclasts and osteoblasts) and it inhibits the secretion of parathyroid hormone, which signals calcium release from bone matrix. Importantly, it has a role to stimulate the immune system, promoting phagocytosis and anti-tumor activity among other functions.

The body produces vitamin D when bare skin is exposed to the sun, hence the term �sun vitamin�. Exposure to sunlight for at least 15 minutes two to three times a week produces adequate quantities of this vitamin for the body�s needs. It is estimated that the body can produce more than 20000 IU (international units) of vitamin D with just 20 minutes of sun exposure.. Once adequate amounts of vitamin D have been formed the body, excess amounts formed are rapidly degraded to protect from overload, in the event of prolonged exposure to the sun. However, conditions such as cloudy skies, northern climates, and atmospheric pollution, limit solar ultraviolet radiation exposure and restrict our ability to replete vitamin D stores.

Vitamin D can also be obtained from dietary sources. It is lipid-soluble and is therefore stored in fat. That is why we find it in fatty fish (like salmon and tuna), eggs, cod-liver oil and fortified milk. In our daily diet, 3 servings of milk (about 250 ml) provide us with approximately 900 mg of calcium and 300 IU of vitamin D.

The recommended daily intake (RDI) of vitamin D is 200 IU for infants, youths and adults up to the age of 50 years. The requirement increases to 400 IU for adults ages 51 to 70 and to 600 IU for people older than 70 years. The RDI and the normal reference values for vitamin D in the blood, are based on levels reported to the prevent rickets and osteomalacia, the two main diseases attributed to lack of this vitamin. Rickets is a childhood disease characterized by poor growth and bone weakness, while osteomalacia is the clinical expression of vitamin D deficiency in adults and is characterized by demineralized bones, fractures, bone pain and generalized weakness. Osteoporosis represents abnormal weakening of bone structure with demineralization of the skeleton, and may also be associated with low levels of vitamin D.

Recent studies confirm that optimal vitamin D status is achieved when the 25- OH vitamin D level in the blood is more than 30 ng/ml. Levels between 10-30 ng / ml represent vitamin D insufficiency (hypovitaminosis D) which can either be moderate (21-30 ng/ml) or severe (10-20 ng/ml). Vitamin D levels below 10 ng/ml are considered vitamin D deficiency and have serious consequences. We now know that long before the full clinical presentation of painful osteomalacia, hypovitaminosis D may cause non-specific symptoms such as persistent musculoskeletal pain regardless of age, gender and ethnic origin.

It is worth noting, that a significant proportion of the population has insufficient levels of vitamin D, mainly due to lack of sun exposure, especially during the winter months, which is not compensated by the usual diet. Indeed, today many of us work in buildings with sealed and tinted glass windows and drive everywhere with very few opportunities to walk in the sunlight. During our limited sun exposure opportunities we frequently use a sun screen lotion further obstructing the beneficial effects of sunlight. In areas above 40˚ latitude (e.g. New York, Northern California), sunshine adequate for vitamin D synthesis in the skin is restricted to the months from May through September. Therefore, a large proportion of the population in the United States is at increased risk for vitamin D deficiency

The prevention of hypovitaminosis D has important public health implications. Millions of health care dollars are spent in dealing with the illnesses and complications associated with this problem and additional funds are lost due to curtailed productivity on a societal level. Since sun exposure has its limitations, the diet is our primary source for this vitamin to ensure an intake of at least 1000 IU daily.

The proper diet must be rich in fatty fish such as salmon, mackerel and sardines, mushrooms (Shitake, sun dried, provide 1600 international units per 100 grams), free-range eggs and fortified milk products. Supplementation of vitamin D and calcium is advisable, especially for children and the elderly. Finally, regular, weight-bearing exercise ensures that calcium absorbed through the activity of vitamin D is used to mineralize the skeleton. Similar to a musical composition, health is ensured through harmony in diet and exercise.

More on the maintenance of metabolic harmony will be discussed in our next article *.

* This article is part of medical communication produced by the MEZITIS EDUCATION AND RESEARCH INSTITUTE for the print media, television and radio programs(Cosmos FM “����� ��� ���” every Saturday at 12:30 pm on 91.5 FM and the internet, live streaming, at gaepis.org) focusing on topics in general health, metabolism and nutrition.

Decades ago, American children faced a dreaded daily routine to prevent rickets and promote overall health: swallowing cod liver oil.

“Before the 1930s, when milk began to be fortified with vitamin D in this country, it was very, very common that children would have been given cod liver oil as a source of vitamin D,” said Allen Knehans, professor of nutritional sciences at the University of Oklahoma Health Sciences Center.
However, a report issued this month by 16 experts said cod liver oil is not a good source of vital vitamin D because the oil also includes toxic levels of vitamin A.

“Americans continue to consume multivitamins and/or cod liver oil containing disproportionately small amounts of vitamin D but detrimental quantities of vitamin A,” the experts said in the report in the Annals of Otology, Rhinology & Laryngology. The high level of vitamin A in cod liver oil “will mask the benefit of adequate vitamin D nutrition,” it said.

Knehans, who was not involved in creating the report, said vitamin A is “clearly toxic” and that high doses over a long period could result in blurred vision, stupor, even coma. “It can be pretty serious.”

The report lauded many apparent benefits of vitamin D, from reduction of influenza and respiratory infections to increased immunity and even prevention of cancer, diabetes and chronic diseases. It also warned of dangers of vitamin D deficiency, including autism, asthma and autoimmune diabetes.

Diet alone cannot solve the problem, the scientists said.

They also said many multivitamins contain far too much vitamin A and far too little vitamin D. They called on federal officials to boost the recommended levels of vitamin D, saying “current official guidelines and limitations for vitamin D intakes are scientifically indefensible.”

Federal guidelines urge people to have a daily vitamin D intake of 200 IU for infants to 600 IU for those 71 and older.

Omega 3 supplements are a very good way to increase your Omega 3 levels. Usually I would recommend eating the food instead of taking a supplement. In this case I believe in taking supplements. For Example, Krill is not really eaten as a food. The mercury levels in fish are getting dangerous. I am not sure you can eat enough walnuts to increase your levels. To learn more about any supplements below or to learn more about omega 3 Please click the link(s) below.

Supplements Include:

Fish Oil

Flaxseed oil

Krill oil

Salmon oil

Shark liver oil

Seal oil

Emu oil

Evening primrose oil (not actually an Omega 3 but worth mentioning)

What is the Best omega 3 Supplements?

I personally believe Omega 3 Krill is the best choice. But I take Krill in the spring and summer. Then in late Fall I switch to Cod Liver oil for the added Vitamin D. I have read much research that says Vitamin D is very important. It’s the Sunshine Vitamin. If you get enough Sunshine you should have adequate levels of D. I am an Avid surfer. Late spring or early summer I can get rid of the wetsuit. Then I can get plenty of Vitamin D kicking. Once I put that wetsuit back on is around the time I return to Cod liver oil. You have to make this decision yourself. If you think you get plenty of Vitamin D stick with the Krill year round. Other Types of Omega 3 Supplements.

Explanation of Each Supplement:

Omega 3 Flaxseed Oil

Flaxseed oil is made by the oil of flax seeds. It is very high in ALA. ALA Omega 3 is a type of fatty acid which has been suggested to be helpful in many of the health problems of today. Please see the Omega 3 Benefits to see a more in depth discussion on benefits of flax seed oil - Omega 3. Flaxseed is a blue flowering plant form western Canada. Flaxseed oil is very main stream now. It is good to see alterntive health ideas hitting the public.

Omega 3 Fish Oil

There are many quality nutritional pure fish oil essential fatty acids out there to increase your omega 3 levels. The dietary types of pufa (polyunsaturated fatty acids) or omega 3 you are trying to increase are DHA and EPA. These vitamins and capsules are full of health and you buy them from many companies. Please read the link to find out reasons omega 3 fish oil may not be the best choice.

Omega 3 Krill Oil

Krill oil is from shrimp like animals that inhabit the cold ocean areas of the world, primarily the Antarctic and North Pacific Oceans. Even though these animals are so small 1 to 5 centimeters they make up the largest biomass in the world. These pink, translucent animals congregate in large, dense masses called “swarms” or “clouds,” that turn areas of the ocean’s surface pink. Krill are very important in the food web since many animals

eat them. They are at the bottom of the food chain. This is very important in keeping the heavy metal levels down.

Omega 3 Salmon Oil

Salmon oil is the best known for increasing Omega 3 levels. They are also known to some as a trout. They are born in fresh water. They then mature in the ocean and swim back up stream to have their little babies. According to some they swim back to the exact same spot they were born to have the little guys.

Omega 3 Shark Liver Oil

Shark Liver Oil has one of the highest levels of Omega 3 oils. The oil comes from deep water sharks. I have to admit I was surprised to find Shark oil as containing high levels of Omega 3. I like to go as low on the food chain as possible.

Sharks are on the top of the food chain. I did not read much on Shark oil having high levels of Mercury and heavy metals. You should be concerned about high levels. Sharks are on the top of the food chain. Heavy Metal Levels like that tend to build the higher on the food chain you go.

Sharks are also one of those animals that are not having the best time of it. I think they are over fished and not respected enough. I do like the added health benefits of sharks. You will see in the next section how sharks have squalene and Alkylglycerols. These two additional components seem to benefits a lot of the health issues Omega 3 benefits. Omega 3 and the squalene and Alkylglycerols probably result in a synergistic effect - increasing the benefits. I still would make another choose if trying to increase you Omega 3 levels.

Omega 3 Seal Oil

The Oil comes mainly from Harp Seals. The Harp Seals are found in the arctic regions of the world. They are still hunted in Canada. The oil is found in the flesh. The harp seal apparently has another type of omega 3 called DPA. This omega 3 has been linked to

1. Healthy pregnancy

2. Normal weight of the baby

DPA is called the last piece in the puzzle as far as Omega 3 goes. It has been linked to prevention of heart disease and reducing the hardening of the arteries (high cholesterol). This is the least known and publicized omega 3 supplements. Some are trying to increase the public’s knowledge.

Conclusion

There are other options to increase your omega 3 levels such as hemp oil, emu oil and chia seeds and many more. The important thing is to know that there are many health benefits to increasing your omega 3 levels. Please click the link below to learn more about the omega 3 health benefits. Omega 3 appears to be one thing you

You are female, over 50, post-menopausal and you keep breaking bones. In fact, you need a hip or knee replacement. The diagnosis? Most likely, your problem will be blamed on osteoporosis.

But the real reason you have brittle bones could be a vitamin D deficiency.

In a recent review of women with osteoporosis hospitalized for hip fractures, 50 percent were found to have signs of vitamin D deficiency, according to Dr. Kenneth Mathis, chairman of orthopedic surgery at the Methodist Center for Orthopedic Surgery in Houston, Texas.

It isn’t only older women who are suffering due to the deficiency. “I am seeing many active, young women and men who have dangerously low vitamin D levels,” said Dr. Mathis.

Osteoporosis is a condition characterized by abnormally porous bone that is fragile and tends to be compressible like a sponge, rather than strong and dense like a brick. In the U.S., more than 10 million people have osteoporosis and an additional 34 million more have low bone density.
The bone disorder is a serious health problem in the U.S. In fact, 50 % of white women will experience a bone fracture due to osteoporosis in her lifetime and 20 % of those who experience a hip fracture will die within a year of the fracture.

A long-term deficiency of vitamin D contributes to osteoporosis because it reduces calcium absorption. The vitamin regulates the amount of calcium that remains in the blood and how much moves into bones and teeth. In addition, vitamin D has also has been found to reduce the risk of breast, colon and ovarian cancer.

“I believe if these people begin taking the daily recommended amount of vitamin D when they are younger, and get their levels tested regularly, that they might be able to prevent osteoporosis and certain cancers when they get older,” Dr. Mathis stated.

Sources of vitamin D include fortified milk, cod liver oil, certain fish (sardines, tuna, salmon and mackerel), yogurt and sunlight. Unfortunately, people who wear a sunscreen with a SPF of 8 or more may have a difficult time converting sunlight into vitamin D.

According to Dr. Mathis, most adults over age 50 should take a daily supplement of vitamin D, if they don’t think they are getting the daily recommended amount (adults under age 50, including pregnant women, need 200 IU of vitamin D daily, people over age 50 need 400 IU daily and those over 70 need 600 IU per day).

However, taking too much vitamin D is not a healthy idea. Dr. Mathis noted the correct amount is important because vitamin D is stored in the liver and in fatty tissues. The vitamin is not water soluble like B vitamins or vitamin C so it cannot leave the body as easily if taken in excess. Vitamin D in very high dosages can build up too much calcium in the blood, leading to kidney stones and/or kidney failure.

One of Dr. Mathis’ patients, sixty-year-old Darlene Yates, was found to have a vitamin D deficiency and she has begun a strict vitamin D regimen to build up her levels following several episodes of broken bones.

She reports her energy has improved and she feels better in general after the treatment.
“I’m hoping that I can get to where I don’t break any more bones and have to have any more surgeries,” Yates said. “If I would have known about the link between vitamin D and bone weakness 40 years ago, you can bet I would have done something about it.”

Real men should eat liver (or carrot juice, or sweet potatoes), not vitamin supplements. That’s because yet another study has come out questioning the value of megadoses of vitamins. The BBC, ABC, and Science Daily have versions of the story. The advice, as I suggested in an earlier post on this topic, is to get your vitamins and antioxidants from real food instead of pills when possible. Forgotten where vitamins naturally come from? Here’s a quick refresher (foods are listed in order of decreasing vitamin richness):

Vitamin A
Organ meat (liver, giblets), carrot juice, sweet potato (with peel), pumpkins, carrots, spinach, collards, kale

Vitamin B -6
Potato, banana, garbanzo beans, chicken breast, oatmeal, pork loin, roast beef

Vitamin B -12
Mollusks, liver, trout, salmon, beef, yogurt, haddock

Vitamin C
Guava, red sweet pepper, kiwi, orange juice, green peppers, grapefruit juice, strawberries

Vitamin D
Cod liver oil, salmon, mackerel, tuna, sardines, milk

Vitamin E
Sunflower seeds, almonds, cottonseed oil, safflower oil, hazelnuts, turnip greens, tomato paste

Mothers everywhere probably will not be surprised to hear that they were right. Drinking your milk is, of course, good for you. Not only is milk chock-full of calcium, most milk has been fortified with vitamin D — and both nutrients are necessary for good bone health, among other things. And in recent years, a growing body of research has caused experts to conclude that many adults, particularly those over 50, are not getting enough calcium or vitamin D, says Dr. Michelle Germain, a part-time faculty member in the Department of Gynecology and Division of Urogynecology at Greater Baltimore Medical Center.

What is vitamin D?

Vitamin D is a fat-soluble vitamin. It is absorbed from food through the GI [gastrointestinal] tract and also is made by the body. The body needs it because it helps with absorption of calcium and phosphorus, both of which the body needs for bone health.

You said that, in addition to absorbing vitamin D from food, the body also manufactures it. How does the body make vitamin D?

The skin manufactures the vitamin D with the help of ultraviolet rays from the sun. So you need sun exposure to make it. Once we have vitamin D in our bodies, the liver and the kidneys convert the vitamin D into the active form that is used for bone health.

What foods contain vitamin D?

Cod-liver oil is the best way to get vitamin D, but we don’t see many people taking that these days. So other really great sources of vitamin D are fish, such as salmon, mackerel and tuna, and vitamin D-fortified foods, such as dairy products and cereals.

What happens if we don’t get enough vitamin D?

You can become vitamin D-deficient. Children can develop “rickets,” in which the bone doesn’t properly mineralize, and the children develop very soft bones and deformities of their skeleton. In adults, too little vitamin D can lead to osteoporosis. [Too much vitamin D, on the other hand, can make the intestines absorb too much calcium.]

How pervasive is rickets?

In developed countries like the United States, it is pretty uncommon because we fortify so many foods with vitamin D. But there has been a resurgence of rickets in African-American infants and children in poorer states, especially in the South such as Tennessee and Mississippi. The resurgence is being caused by poverty and poor nutrition. It also has to do with darker pigmentation of the skin, which converts sunlight less effectively into vitamin D.

Rickets also is more prevalent in immigrants from Africa, the Middle East and Asia because of their diets before they arrive in the United States and because they may not have enough money to afford good nutrition once here. Again, if they have darker skin, they are not converting UV rays into vitamin D as effectively as people with lighter skins.

Are there other populations for which vitamin D is particularly important?

Older women. If older women are vitamin D-deficient then they are at increased risk for osteoporosis. This is of special concern for menopausal women because once their estrogen levels drop, they begin to lose bone. The vitamin D is necessary to absorb calcium and utilize it in bone formation. And people who have any kind of gastrointestinal illness like Crohn’s disease or celiac disease or any kind of liver disease also are at increased risk for vitamin D deficiency.

Are there any symptoms of vitamin D deficiency that might occur before bone loss?

Unfortunately, there are really no symptoms of it until you are diagnosed with osteoporosis.

What do you tell your patients about vitamin D?

Children and young adults need to consume a diet that is rich in vitamin D-fortified foods. At least 15 minutes of exposure to sunlight twice a week should be adequate to make sufficient amounts of vitamin D. But I also tell them that if you put on sunscreen with an SPF greater than 8, it can interfere with making vitamin D, so diet is very important. Particularly in winter, they should concentrate on eating a diet with plenty of vitamin D-rich foods.

What do you tell adults?

If a woman has osteoporosis, she should ask the doctor if she is potentially vitamin D-deficient. Very often, after a woman has a hip fracture, we check her vitamin D level, and it turns out to be ridiculously low. So, if you have osteoporosis or a fracture, ask about your vitamin D level.

How much vitamin D do we need?

Last year, the National Osteoporosis Foundation released new recommendations about vitamin D. The National Institutes of Health also are due to release this spring new guidelines. According to the National Osteoporosis Foundation, adults under age 50 need 400 to 800 IU [International Units] of vitamin D3 daily. [Also called cholecalciferol, vitamin D3 is the kind of vitamin D that best enhances healthy bones.] And menopausal women and adults over the age of 50 need 800 to 1,000 IU of vitamin D3 daily.

Sixty-year-old Darlene Yates has had two hip replacements, a knee replacement and this past year shattered her left femur while she was walking in her neighborhood. Her diagnosis seemed obvious — osteoporosis. But it turns out she had bone weakness caused by a vitamin D deficiency.

“I thought with my age and all my broken bones that I definitely had osteoporosis,” Yates said. “The low vitamin D levels really took me by surprise.”

Vitamin D promotes the absorption of calcium and phosphorus. It regulates how much calcium remains in the blood and how much makes its way to the bones and teeth. It also has been found to reduce the risk of breast, colon and ovarian cancer. Vitamin D deficiency contributes to osteoporosis by reducing calcium absorption and osteoporosis is an example of the long-term effects of vitamin D deficiency.

In a recent review of women with osteoporosis hospitalized for hip fractures, 50 percent were found to have signs of vitamin D deficiency. Low levels are most often seen in older women; however, times appear to be changing.“I am seeing many active, young women and men who have dangerously low vitamin D levels,” said Dr. Kenneth Mathis, chairman of orthopedic surgery with The Methodist Center for Orthopedic Surgery. “I believe if these people begin taking the daily recommended amount of vitamin D when they are younger, and get their levels tested regularly, that they might be able to prevent osteoporosis and certain cancers when they get older.”

Sources of vitamin D include fortified milk, cod liver oil, fish such as sardines, tuna, salmon and mackerel, some yogurt and breakfast cereals, and the sun. However, if you wear an SPF of eight or more, you will have a tough time converting the sunlight into vitamin D.

Most adults over age 50 need to take a daily supplement of vitamin D if they don’t think they are getting the daily recommended amount. Adults under age 50, including pregnant women, need 200 IU of vitamin D daily. A person over age 50 needs 400 IU daily and it goes up to over 600 IU at age 70.

Mathis says taking the correct amount is important because too much vitamin D can be toxic. Vitamin D is stored in the liver and in the fat tissue. When you take too much it cannot leave the body as easily as water soluble vitamins such as vitamin C. The excess vitamin D can lead to too much calcium in the blood, which can cause kidney stones and/or kidney failure.

Yates has begun a strict vitamin D regimen to build up her levels. She says she has more energy than she ever has and is feeling better.

“I’m hoping that I can get to where I don’t break any more bones and have to have any more surgeries,” Yates said. “If I would have known about the link between vitamin D and bone weakness 40 years ago, you can bet I would have done something about it.”

DR. DAVID WONG
The Guardian

Question: I am the mother of three lovely children. When our third child was born six weeks ago, our family doctor told me that I should give him vitamin D everyday because I am breast-feeding him.

I breast-fed our two older children but I never gave them any vitamin D, and they are perfectly fine. I wonder whether I should follow our doctor’s suggestion.

Answer: Your doctor is correct, you should give him vitamin D 400 international units (IU) a day because you are breast-feeding him. Recent research shows that many children and adults in Canada are not getting enough Vitamin D, and this can affect our health.

Vitamin D is normally produced in our skin when it is exposed to ultraviolet light rays from the sun. If a white-skinned person in a bathing suit is exposed to summer sun around noon time for 15 to 20 minutes, about 10,000 IU of vitamin D will be produced by the skin. However, if a dark-skinned person is exposed to the sun in the same way, only about 2,000 IU of vitamin D is being produced.

Melanin, a dark pigment present in the skin, blocks the ultraviolet rays. As a result, less vitamin D is produced. In the same way, if we put on sunscreen lotion or wear long-sleeve shirts and long pants to prevent sunburn, the amount of vitamin D produced in the skin also decreases.

Vitamin D is best known for the growth and development of bones in children. The importance of vitamin D was first discovered in England in the mid-17th century. Physicians at that time saw young children with bone deformities they called rickets. They recognized rickets was most common during winter months and they suspected a link between rickets and exposure to sunlight.

Over time, cod-liver oil was found to be effective in the prevention and treatment of rickets. As a result, vitamin D was discovered and was shown to be important for calcium absorption from the intestines and deposition in the bones.

Because of the importance of vitamin D in the prevention and treatment of rickets, all cow’s milk (except yogurt drinks), soy milk and some orange juice sold in North America are fortified with vitamin D. For a long time, many people, including physicians, thought that these measures had eradicated rickets completely.

In 1984, several Canadian researchers reported 16 Inuit infants living in high Arctic coastal communities with vitamin D deficiency rickets. This report rekindled interest in vitamin D and the fact that rickets still occurs in spite of years of fortification of cow’s milk and other products.

In 2007, another group of researchers reported a two-year study which identified 104 children across Canada with rickets due to a lack of vitamin D in their diet. Most of these children lived in the far north, many were breast-fed and had no vitamin D supplement given to them. Their mothers also lacked vitamin D because of limited exposure to the sun and did not have enough vitamin D from their diet or supplementation during pregnancy and while they were nursing.

These findings highlighted the importance of lack of sun exposure for Canadians, especially during the fall and winter months, and a deficiency of vitamin D in the body. Unless the diet is rich in vitamin D, supplementation is necessary to prevent a vitamin D deficiency state.

Aboriginals have changed their diet in recent years. They used to hunt and fish and stay active outdoors much of the time. Their source of food used to have good amount of vitamin D. However, with a more westernized diet, their intake of vitamin D has decreased.

Although breast milk is the most natural and nutritious food for babies, it does not contain enough vitamin D unless the mother’s vitamin D level is high, either from lots of sun exposure or taking significant amount of vitamin D (from food or supplements, or both) during pregnancy and breast-feeding.

Because of these findings, the Canadian Paediatric Society now recommends that all breast-fed babies should be supplemented with 400 IU of vitamin D everyday during the first year of life.

For those who live in areas further north than approximately Edmonton, Alta., the amount of vitamin D required from all sources should be increased to 800 IU per day between October and April.

It is also recommended that pregnant and breast-feeding women should receive 2,000 IU of vitamin D a day. This recommendation is based on the lack of sunshine in Canada, as well as the importance of vitamin D in the development of bones and other organs in babies before and after birth.

Recent research also suggests vitamin D is important for most parts of the body, not only for bones. All chemicals interact with cells in the body through receptors, which are like doors that allow chemicals to enter cells. Most cells in the body have vitamin D receptors, which means that vitamin D is important in the function of most cells in the body.

A number of medical conditions have been linked to a lack of vitamin D. These include osteoporosis, asthma, rheumatoid arthritis, multiple sclerosis (MS), inflammatory bowel diseases (Crohn’s disease and colitis), diabetes, disturbed muscle function, tuberculosis and several types of cancer. Many of these diseases are much more common in countries like Canada and northern Europe.

Because of recent research findings, the Canadian Cancer Society recently recommended that all white adults take 1,000 IU of vitamin D a day in fall and winter, while non-whites should take this amount year-round.

Most multivitamin pills only have 400 IU of Vitamin D, although 1,000 IU vitamins D pills are becoming more available recently.

Although vitamin D is very important for the body in many ways, we still don’t know what is the maximum safe dose that one can take.

More does not necessary mean better or safe. Excessive amount of vitamin D can increase calcium level in the blood and cause calcium deposits in places where it shouldn’t happen.

Until research can answer some of these questions, the safest way is to follow the recommendations of these professional societies. In the meantime, it likely won’t hurt for you to get some natural vitamin D on a sunny day, although this has to be balanced with danger of sunburn and long-term risk of skin cancer.

Dr. David Wong is a consultant pediatrician in Summerside and president of the Community Paediatric Section of the Canadian Paediatric Society. His column is in The Guardian every four weeks. You can find his previous columns at www.askdrwong.ca. If you have a question for Dr. Wong, mail it to: Ask Dr. Wong, P.O. Box 21018, Summerside, P.E.I., C1N 6A1.

It sounds too good to be true… a little inexpensive pill that could block the development of some cancers, strengthen bones, prevent multiple sclerosis and alleviate winter depression.

But it’s not science fiction. The “new aspirin” could be Vitamin D. Just as we discovered that aspirin can guard against heart disease, Vitamin D could become a useful weapon in the fight against MS, osteoporosis, mild depression and one of the most devastating diseases of our time – cancer.

“As time has gone by, Vitamin D has raised its head as a sort of ambrosia for cancers,” says Dr. Louise Parker, an epidemiologist and a world expert in the environmental exposures that can lead to cancer. Or, in the case of Vitamin D, the lack of exposure.

“One of the most important sources of Vitamin D is from the sun and through your skin,” says Dr. Parker.

“Many parts of Canada don’t get much sun in the winter. We’ve also been telling people to cover up and use sunscreen to prevent skin cancer. Sunscreen actually impairs your (skin’s ability) to make Vitamin D.”

So the Canadian Cancer Society recommends that during the winter, Canadians take at least 1,000 units a day of Vitamin D, dubbed “the sunshine vitamin.”

Dr. Parker says 1,000 units a day is well beyond what you can obtain from your diet. Vitamin D is a bit of a rare vitamin, appearing only in fatty fish, cod liver oil and egg yolks. Even if you were to sunbathe in southern climates, you would not take in 1,000 units.

“If you were to lie naked on a beach in the Bahamas, and I don’t recommend that because of skin cancer, you cannot get up to the equivalent of 1,000 units of Vitamin D a day,” says Dr. Parker.

She notes Vitamin D as a factor is turning up in study after study. It turns out people with lung and colon cancer are Vitamin D deficient. And it helps the body absorb calcium. In a study examining whether women who took Vitamin D had a lower risk of osteoporosis, it was found the women taking Vitamin D had stronger bones than those who did not take the vitamin. Years later, researchers went back to that study and found that the women who took Vitamin D also had fewer cancers.

But before Vitamin D becomes the “new aspirin,” more research needs to be carried out.

Vitamin D works in very complicated ways, she says. It changes the way cells work. In fact, there is medical speculation that it may block cancer cell proliferation or improve immune system functions. But its role is not fully understood.

Lifestyle also has to be part of the equation. Dr. Parker is looking at how obesity, which we know can cause cancer, and exercise, which we know prevents cancer, could interact with Vitamin D. “At the population level, I am trying to understand how all these things fit together,” says Dr. Parker. “It’s very complex.” Dr. Parker describes it as looking for a piece of a jigsaw puzzle. “We know some of the jigsaw pieces, but not all,” she says.

Meanwhile, there is very little evidence that taking Vitamin D can harm you. Perhaps in huge doses it could cause kidney stones, but that has not been proven.

“On the average, 1,000 units a day is safe and is probably effective in reducing the risk of colon cancer, and maybe other cancers as well,” says Dr. Parker.

So does she take Vitamin D and recommend it? Absolutely. “I take 1,000 units of Vitamin D – one day on and one day off,” she says.

Source:

Dalhousie University via (http://www.newswise.com)

Dalhousie University (2008, February 16). A Ray Of Sunshine In The Fight Against Cancer:

Cod liver oil, a long-used source of vitamin D, may have the unexpected effect of lowering bone mass, a new study suggests.Norwegian researchers found that among more than 3,000 middle-aged women, those who took cod liver oil as children generally had lower bone mass than women who had not used the fish oil.

Because sunlight is needed to trigger the synthesis of vitamin D in the skin, people in Nordic countries are at particular risk of vitamin D deficiency. Cod liver oil is a traditional source of supplemental vitamin D, and is still widely used in Norway, where few foods are fortified with the vitamin.

Many people also take cod liver oil as a source of heart-healthy omega-3 fatty acids, or to ease arthritis symptoms.

Given the role of vitamin D in maintaining healthy bones, the new findings are “unexpected” and “paradoxical,” the researchers note in the American Journal of Epidemiology.

They speculate, however, that the high vitamin A content in cod liver oil could be to blame.

Vitamin A accumulates in body fat, and excessive levels may have a negative effect on bone metabolism and actually raise fracture risk, explained Dr Siri Forsmo, the lead researcher on the study and an associate professor at the Norwegian University of Science and Technology in Trondheim.

Too much vit A to blame
It’s possible that cod liver oil, on top of the traditionally vitamin A-rich Norwegian diet, provided some of these women with too much of the nutrient, Forsmo told Reuters Health.

Since 2002, Norway has required that cod liver oil producers cut the supplement’s vitamin A content by 75 percent - from 3,300 International Units per dose to 825 IU. Forsmo said she is unaware of any other countries that have made similar moves.

In the US, the recommended daily intake for vitamin A is 3,000 IU for men and 2,310 IU for women; for children, the recommendation is between 1,000 and 2,000 IU per day.

In contrast to the US and certain other countries, where milk and many breakfast cereals are fortified with vitamin D, relatively few foods in Norway have added vitamin D, Forsmo noted. Butter, margarine and one type of low-fat milk are the exceptions.

So cod liver oil remains a major source of vitamin D there, Forsmo said, adding that she still takes it during the winter.

Importantly, the researcher noted, the current study looked at bone mass, and not whether women who used cod liver oil as children actually had a higher rate of bone fractures. That is a question for future studies. - (Amy Norton/Reuters Health)

SOURCE: American Journal of Epidemiology, February 15, 2008.