Vitamin Information Center

Over the past few years the sun has gotten a bad rap. Too much sunshine can put you at risk for skin cancer. And an overdose of sun can also lead to nasty sunburns, or even heatstroke.

But the sun isn’t always bad for the body. Scientists have known for years that the sun is a great source of vitamin D. This vitamin naturally boosts the immune system, your body’s defense against disease. Now mushrooms bathed in ultraviolet (UV) light — like that from the sun — can help you get some of this valuable vitamin.

Each year there are more and more studies released that suggest if you want to be healthy, vitamin D is where it’s at. Vitamin D strengthens your heart and bones, and can prevent asthma and some forms of cancer and diabetes.

Some foods, like fish and eggs, are naturally brimming with the vitamin. And others, like milk and some cereals, are fortified with vitamin D. But you would need to consume a lot of milk and cereal to get your daily dose of vitamin D. Sunlight still reigns king as the best source for vitamin D.

Recently scientists have shown that specially treated mushrooms could give people a vitamin D boost. U.S. Department of Agriculture researchers in California treated portabella mushrooms to suntanning sessions of up to 18 minutes. The mushrooms didn’t develop a bronze glow or complain of heat stroke though. Instead each mushroom produced nearly 4 micrograms of vitamin D per gram of tissue. When white mushrooms were given similar sun treatments, these fungi boasted extra vitamin D, too. Now both kinds of vitamin-infused ‘shrooms are on the market. So if you like mushrooms, you could munch your way to a higher daily dose of Vitamin D.

Depending on a person’s age, people should get between 5 and 15 micrograms (or 200 to 600 international units) of vitamin D each day. Without these amounts, people are prone to get diseases like rickets, which causes distorted, soft bones. These numbers, though, are really just a minimum. Now some scientists suggest it’s better to get as much as five times the recommended vitamin D dose each day.

Having more foods with Vitamin D is a good thing, since there are also several factors that make it hard to get enough of the vitamin from just the sun.

One factor influencing elderly people’s vitamin D intake is that they often spend less time outdoors. Therefore, they need more vitamin D in their diet. And if you spend a lot of your time indoors, playing video games or on the computer, you may need extra vitamin D from your food, too.

Skin color and weight also help determine a person’s vitamin D needs. Darker skin filters out more of the sun’s UV light, so people with darker skin need more sun exposure to make necessary amounts of vitamin D. For unknown reasons, heavier people also need a greater amount of UV light to enable vitamin D production.

And latitude — how far north or south you live — can play a major role in the sun’s ability to help you get adequate vitamin D amounts. As you get farther away from the equator, the amount of UV-filtering atmosphere increases. This means that at higher, more northern latitudes, people get less UV rays. So, if you live in a state like Alaska, most of the year you can’t get enough sun to trigger the vitamin’s production by your skin.

Eating foods enriched with vitamin D or taking a daily vitamin may not be as satisfying as breaking out your bathing suit and lying in the sun. But the right foods and supplements can help keep you healthy until summer’s rays are here again.

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.

The human body is an amazing factory, with all kinds of parts working together to make chemicals necessary for good health. But one thing it can’t make on its own is vitamin D. Research shows that defect can be troubling, especially among children.

To create vitamin D, which plays an important role in bone health and development, the body needs exposure to sunlight. As some countries move into autumn, the days get shorter and colder and exposure to sunlight decreases, making the colder months of the year a crucial time to watch vitamin D intake. Supplements can play an important role but one question is, how much?

Most of a child’s bone mass is built up early. A vitamin deficiency can prevent a child from building adequate bone mass now, and they won’t be able to make it all up later.

Although a study released this week found that vitamin D deficiencies are common in children around the world, there is minimal data on how much supplementation is necessary or safe.

Vitamin D is a fat — soluble vitamin directly or indirectly involved in several key body processes: regulating calcium and phosphorus levels in the blood, promoting bone formation and mineralisation, restricting parathyroid hormone secretion and promoting anti-tumour activity.

A review of medical literature on the vitamin published last year in The New England Journal of Medicine found that vitamin D is also associated with a reduced risk of type 1 diabetes in children, and may inhibit future hip fracture.

The main source of vitamin D is sunlight, which the body uses to convert vitamin D into a useable form. It’s also found naturally in eggs and fatty fish like salmon or tuna, and milk and some breakfast cereals are fortified with the vitamin.

The Institute of Medicine recommends that children get 200 IUs of vitamin D daily, but some experts say that up to 800 IUs is better.

The new study found that high doses of the vitamin were safe for children, whether taken over the short-term or for a longer period of time, and helped increased bone mass in 10 to 17 year olds.

A study released this summer found that even children who are otherwise healthy can have low levels of vitamin D, resulting in low levels of bone mineral content.

The risk for low vitamin D levels begins in infancy —breast milk, like cow’s milk, is naturally low in vitamin D. And if a mother doesn’t have enough vitamin D, her breast milk won’t either.

A vitamin D deficiency can affect bone growth even if there are no obvious problems.

A bottle of vitamin supplements
The American Academy of Paediatrics says that rickets, bone softening that can lead to fractures and deformity, in infants due to low vitamin D intake is seen in several US states.

The agency recommends that breast-fed infants receive vitamin D supplement drops.

Children at risk
“It is recommended that all infants, including those who are exclusively breastfed, have a minimum intake of 200 IUs of vitamin D per day beginning during the first two months of life,” said a clinical report for the health agency done by Dr Lawrence Gartner and Dr Frank Greer.

“In addition, it is recommended that an intake of 200 IUs of vitamin D per day be continued throughout childhood and adolescence, because adequate sunlight exposure is not easily determined for a given individual.”

The risks to bone health don’t end in infancy.
A Canadian study released last year found that despite guidelines for its prevention, vitamin D-deficiency rickets in childhood is still seen in the country, with an annual incidence of 2.9 cases per 100,000.

Children living in countries where exposure to sunlight is low had the highest incidence, and most of the affected children had medium to dark skin tones and had been breast fed.

“Since there were no reported cases of breast-fed children having received regular vitamin D (400 IU/d) from birth who developed rickets, the current guidelines for rickets prevention can be effective but are not being consistently implemented,” the study concluded.

Adequate vitamin D levels in the blood are important because the body can’t absorb dietary calcium without vitamin D, so in its absence it steals calcium from the bones, which increases the risk of rickets, osteoporosis and fractures.

This also places teenagers at risk because they have weaker bones that are more likely to fracture.

Children at particular risk include infants who are breast-fed exclusively and don’t receive supplementation, children who use sunscreen in summer, children who don’t use sunscreen in the summer but spend less than 15 minutes a day in direct sunlight, children who receive no supplementation in the winter, and children with chronic diseases that affect fat malabsorption, such as cystic fibrosis or celiac disease, according to the Hospital for Sick Children.

TORONTO (Reuters) - The human body is an amazing factory, with all kinds of parts working together to the make the chemicals necessary for good health. But one thing it can’t make on its own is vitamin D. Research shows that defect can be troubling, especially among children.

To create vitamin D, which plays an important role in bone health and development, the body needs exposure to sunlight. As we move into autumn, the days get shorter and colder and our exposure to sunlight decreases, making the colder months of the year a crucial time to watch vitamin D intake. Supplements can play an important role but one question is, how much?

Most of a child’s bone mass is built up early. A vitamin deficiency can prevent a child from building adequate bone mass now, and they won’t be able to make it all up later. Although a study released this week found that vitamin D deficiencies are common in children around the world, there is minimal data on how much supplementation is necessary or safe.

Vitamin D is a fat-soluble vitamin directly or indirectly involved in several key body processes: regulating calcium and phosphorus levels in the blood, promoting bone formation and mineralization, restricting parathyroid hormone secretion and promoting anti-tumor activity. A review of medical literature on the vitamin published last year in The New England Journal of Medicine found that vitamin D is also associated with a reduced risk of type 1 diabetes in children, and may inhibit future hip fracture.

The main source of vitamin D is sunlight, which the body uses to convert vitamin D into a useable form. It’s also found naturally in eggs and fatty fish like salmon or tuna, and milk and some breakfast cereals are fortified with the vitamin. The Institute of Medicine recommends that children get 200 IUs of vitamin D daily, but some experts say that up to 800 IUs is better.

This week’s study found that high doses of the vitamin were safe for children, whether taken over the short-term or for a longer period of time, and helped increased bone mass in 10-17-year olds.

Vitamin D deficiency is particularly a problem for North Americans, research shows, due in part to the higher latitudes at which they live. As well, because of concerns about skin cancer, many people now wear sunscreen, which inhibits the body’s ability to use sunlight to make the vitamin. The Hospital for Sick Children in Toronto says that sunscreen with an SPF above 8 blocks all vitamin D production through the skin. And darker-skinned individuals living in Canada and the United States may be at particular risk because they have more melanin in their skin, which means they need more sunlight than a lighter-skinned person to make the same amount of vitamin D.

A study released this summer found that even children who are otherwise healthy can have low levels of vitamin D, and resulting low levels of bone mineral content. More than 12 percent of the 400 kids studied by researchers at the Children’s Hospital in Boston had levels of vitamin D in their blood low enough to qualify them as deficient, and 40 percent of the children had less than the recommended level
The risk for low vitamin D levels begins in infancy - breast milk, like cow’s milk, is naturally low in vitamin D. And if a mother doesn’t have enough vitamin D, her breast milk won’t either.

A vitamin D deficiency can affect bone growth even if there are no obvious problems. The American Academy of Pediatrics says that rickets (), bone softening that can lead to fractures and deformity, in infants due to low vitamin D intake is seen in several U.S. states. The agency recommends that breast-fed infants receive vitamin D supplement drops.

“It is recommended that all infants, including those who are exclusively breastfed, have a minimum intake of 200 IUs of vitamin D per day beginning during the first 2 months of life,” said a clinical report for the health agency done by Drs. Lawrence Gartner and Frank Greer. “In addition, it is recommended that an intake of 200 IUs of vitamin D per day be continued throughout childhood and adolescence, because adequate sunlight exposure is not easily determined for a given individual.”

The risks to bone health don’t end in infancy. A Canadian study released last year found that despite guidelines for its prevention, vitamin D-deficiency rickets in childhood is still seen in the country, with an annual incidence of 2.9 cases per 100,000. Children living in the northern part of the country, where exposure to sunlight is the lowest, had the highest incidence, and most of the affected children had medium to dark skin tones and had been breast fed.

“Since there were no reported cases of breast-fed children having received regular vitamin D (400 IU/d) from birth who developed rickets, the current guidelines for rickets prevention can be effective but are not being consistently implemented,” the study concluded.

Adequate vitamin D levels in the blood are important because the body can’t absorb dietary calcium without vitamin D, so in its absence it steals calcium from the bones, which increases the risk of rickets, osteoporosis and fractures. This also places teenagers at risk because they have weaker bones that are more likely to fracture.

Children at particular risk include infants who are breast-fed exclusively and don’t receive supplementation, children who use sunscreen in the summer, children who don’t use sunscreen in the summer but spend less than 15 minutes a day in direct sunlight, children who receive no supplementation in the winter, and children with chronic diseases that affect fat malabsorption, such as cystic fibrosis or celiac disease, according to the Hospital for Sick Children.

Because natural sources are so rare, it’s difficult to get adequate vitamin D in the diet. One tablespoon of cod liver oil has 1,360 IUs, a serving of cooked salmon has 360, a cup of fortified milk has 98 and a whole egg has 20. Fifteen minutes of direct sunlight is enough for many people to reach their needs for vitamin D, but darker-skinned people need longer exposure and because winter sunlight in North America is indirect, supplementation may be recommended.

Do you supplement with extra vitamin D? Let us know: HealthMatters@reuters.com

Oily fish: Mackerel is a good source of vitamin D

Vitamin D may offer protection against the most common form of diabetes.

New research shows that, in particular, men with the highest blood level of the vitamin were 72 per cent less likely to develop type 2 diabetes.

There was a reduced effect among women.

Scientists in Finland monitored several thousand people, aged 40 to 74, for 22 years, during which time 412 developed the disease.

Results showed that those with higher levels of vitamin D had the lower risk of diabetes.

It is thought that low levels of vitamin D affect the body’s ability to produce insulin.

Diabetes type 2 is a growing health problem.

There are 1.9 million adults in the UK with diagnosed diabetes, and it is estimated there are another 589,000 unidentified sufferers.

Risk increases with age - less than one per cent of people under 34 have diagnosed diabetes compared with 10 per cent aged 75 and over.

By Helen ChickeringNBC News Channel

Debate is raging over how much sun you should get. For years, we’ve been warned that sunscreen is a must, but now some health professionals are saying some exposure to the sun’s rays is necessary. An American Academy of Dermatology survey finds that ten percent of Americans in their 40s, 50s, 60s and even 70s hit the tanning bed.

Sunlight, even artificial is a prime source of Vitamin D, a nutrient that helps the body absorb calcium and one a growing body of research suggests may also help prevent diseases from cancer to diabetes. Unfortunately, up to half of the population is not getting enough, according to the Duke Diet Center’s Elisabetta Polilti.

“Vitamin D sources are not very common,” she explained.

Oily fish like salmon and fortified milk are among the few dietary sources of Vitamin D. That leaves supplements and sunshine, unless you wear sunscreen.

“The skin lotion is preventing vitamin D from being absorbed,” Politi said.

While it’s doubtful we’ll ever say ’so long’ to sunscreen, the Vitamin D dilemma does have the scientific and medical communities taking a closer look at the safe sun message.

Boston University’s Dr. Michael Holick calls it “sensible sun exposure.”

“Typically maybe five to ten minutes of arms and legs, two to three times a week, followed by good sun protection is a good recommendation,” he said.

It’s a recommendation that has gotten heat from major skin and cancer organizations who’ve noted the rise in skin cancer. All parties do agree people aren’t getting enough of the sunshine vitamin.

©2008 NBC News Channel. All rights reserved. This material may not be published, rewritten, or redistributed.

A study by researchers at the Institute for Cancer Research in Oslo, Norway has given further credence to the claim that the benefits of modest sun exposure outweigh the risk of skin cancer for most people. Johan Moan, the researcher who led the study said, “Modest sun exposure gives enormous vitamin D benefits.”

He estimated that doubling the amount of sun exposure for residents of Norway would double the number of deaths due to skin cancer to 300. However, the great benefit to this would be a decrease of 3,000 people who die from other cancers [1].

The human skin synthesizes vitamin D when exposed to the ultraviolet type B (UVB) radiation in sunlight. Solar radiation is the main source of vitamin D for most people. Modest sun exposure causes a significant amount of vitamin D to accumulate in the body and protect from some internal cancers and other illnesses such as diabetes and rickets. Vitamin D promotes bone mineralization and calcium absorption thus protecting against osteomalacia and osteoporosis. The vitamin also helps the body’s immune system function properly [2]. When deficient, the human body is at great risk of acquiring these conditions and deficiency is linked to heart attacks and mental depression. Most people could experience the benefits by increasing their sun exposure, but not too much as to cause any burning.

Vitamin D deficiency has been measured to be as high as 21 to 58 percent in adolescents and adults in the United States [3].

Several factors reduce individuals’ exposure to sunlight and UVB light rays: the amount of time spent in the sun is the most obvious. Also, more polar latitudes, the time of day such as dusk compared to noon, high cloud cover, smog, and sunscreen use lower the amount of UVB radiation that reaches people.

Geographic latitude plays a significant role. Generally, the farther an individual is from the equator, the more difficult it is to synthesize enough vitamin D. For example, in Boston, MA, from November through February, the average amount of sunlight is inadequate for an individual to synthesize enough vitamin D [4]. Additionally, the researchers at the Institute for Cancer Research in Oslo determined that, given the same amount of sunlight, inhabitants of Australia just below the equator produced 3.4 more times the vitamin D than people in Britain and 4.8 times that of Scandinavians [1].

It’s essential to learn the optimal amount of sun exposure that is healthy for you without causing sunburn. Moan recommended that a person’s daily sun exposure should be about half the time that it would take to burn. Lighter skinned people are more sensitive to sunburn and skin damage, but they are more proficient at creating vitamin D with less sun exposure than a darker skinned person (Please see [5] below for a related, generally accepted theory for skin color variance). Light skinned peoples in Southern United States can synthesize enough vitamin D by exposing their face and arms to the sun without sunscreen for about 15 minutes a few times a week. Dark skinned people need about 5 to 10 times more exposure [2].

A consensus has not been made for how much vitamin D is a healthy level for most people, but it’s generally agreed that for people up to the age of 50, 200 IUs (international unit) is the Adequate Intake (AI). For 51 to 70 year olds, 400 IUs is the AI and for individuals over 70, 600 IUs is recommended. The ability to synthesize vitamin D decreases with age. However, recent studies have shown amounts of vitamin D of 2,000 IUs and higher to be more effective and still safe [6]. If a person works outside under the summer sun for hours in a tank-top and shorts, his skin will have made thousands of IUs. Of course, a baseline tan to prevent burning would be a good idea. Normal body levels of vitamin D can’t reach the level that a large vitamin D pill would produce. The body self-regulates; reducing vitamin D synthesis when levels are getting high from sun exposure.

Is there a difference between taking say, 1,000 IUs in pill form and synthesizing it via UVB radiation? Is putting a 1,000 IU pill in your body versus forming it all over your skin comparable to drinking 8 glass of water at once versus spreading it throughout the day? This, I am unsure of.

Within UVB light are a range of wavelengths. Some are more optimal for vitamin D synthesis than others. A person at sea level will receive these wavelengths when the sun is 45 degrees above the horizon or the UV index for the day is above 3. When the sun is at or above this elevation in the sky, sufficient amounts of vitamin D can be made by the skin in about 15 minutes a few times a week. The area of the planet within the tropics provides this solar elevation daily, but it occurs daily only in the spring and summer seasons of temperate regions, and nearly never in the arctic circles [7]. Seasonal supplementation seems to be appropriate.

Sunscreen with a sun protection factor (SPF) of 8 prevents more than 95% of vitamin D production [11]. So when you lather up with this sunscreen, it will take 20 times longer than usual to make enough vitamin D. This effect was observed during a campaign in Australia to increase sunscreen use to prevent skin cancer. The result was an increase in Australians with vitamin D deficiency [8].

If the minimum level of sun exposure can not be obtained, people should look to their diet for vitamin D. Since few foods contain enough vitamin D, some foods are fortified with vitamin D and supplements can be taken to attain an adequate level.

To complicate matters further, there are 5 forms of vitamin D. The two major forms are vitamin D2 (ergocalciferol) and D3 (cholecalciferol). Both forms are present in human nutritional supplements. When our skin comes into contact with UVB radiation, it synthesizes only vitamin D3. Both of these forms are prohormones, precursors to the vitamin D hormone that goes on to perform all of the beneficial processes that have been mentioned. However, the vitamin D3 form is about 3 times more effective at creating the vitamin D hormone and its duration of action is longer that the D2 form. Supplementing with vitamin D3 would be the wiser choice [9].

UVA and UVB radiation exposure is a double edged sword. Excessive exposure will cause damage to the skin and more importantly, to the DNA inside the cells. With more DNA damage comes a greater chance of developing skin cancer. However, only a small percentage of skin cancers are the type that will metastasize (to spread throughout the body from the origin of formation). The wavelengths of UVA light are longer and penetrate farther into the skin. UVA radiation is a more potent cause of skin cancer than the shorter UVB light.

Skin cancers are among the fastest growing types of cancer in the United States and make up about 1 out of 3 new cancers.

With the rise in popularity of sun bathing, something must be said about tanning beds. Although the time spent in a tanning bed is typically much less than say, an afternoon at the beach, the radiation levels are more intense than from sunlight and the UVA to UVB radiation ratio is much higher than from the sun. The amount of UVA radiation in the light of tanning beds is typically between 3 to 8 times greater than in sunlight [10]. Recall that UVA radiation, and UVB less so, put individuals at risk for DNA damage and skin cancer, but only exposure to UVB radiation will produce vitamin D, which protects against many illnesses. Therefore, it is this author’s humble opinion that, while tanning beds may be more convenient, it is safer to get your healthy glow from the sun and good nutrition.

References:

[1]“Addressing the health benefits and risks, involving vitamin D or skin cancer, of increased sun exposure”((http://www.pnas.org/cgi/content/abstrac…)

[2]((http://www.medicinenet.com/script/main/…)

[3]“Vitamin D Deficiency-The Once and Present Epidemic” (http://www.aafp.org/afp/20050115/editorials.html)

[4](http://healthlink.mcw.edu/article/982088787.html)

[5]“Skin Color Adaptation” (http://anthro.palomar.edu/adapt/adapt_4.htm)

[6](http://www.vitamindcouncil.com/treatment.shtml)

[7]((http://upload.wikimedia.org/wikipedia/c…)

[8]Nowson C, Margerison C (2002). “Vitamin D intake and vitamin D status of Australians”. Med J Aust 177 (3): 149-52. PMID 12149085.

[9]“Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans” ((http://jcem.endojournals.org/cgi/conten…)

[10]Woollons, A., Clingen, P.H., Price, M.L., Arlett, C.F., Green, M.H.L. (1997). Induction of mutagenic DNA damage in human fibroblasts after exposure to artificial tanning lamps. British Journal of Dermatology 1997; 137: 687-692.

[11]((www.motherearthnews.com/Natural-Health/…)

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.

IOWA CITY - If storm after storm is giving you the winter blues, we have some more bad news. It turns out a slip and fall on the ice could be especially dangerous if your vitamin D levels are low. And just about everyone living in Iowa is low right now.

In February our days are shorter and the skies are cloudy. Winter takes its toll on us mentally. But it is also a drain on our vitamin D. Experts say that can lead to all kinds of problems. Registered dietitian Sue Little said, “We’re at more risk for multiple sclerosis, higher risk for diabetes, higher risk for falls and muscle weakness. The list goes on.”

In the summer, Iowans only need to be outside for about 10 minutes to get enough vitamin D. But in February, it is a much different story. Little said, “You’d have to stay outside naked for like five hours to get enough vitamin d synthesis this time of year.”

There is simply not enough sun in Iowa in February to get all the vitamin D you need, so you need to go shopping. Little says a glass of milk a day will get you 10-percent of what you need. Fatty fish like salmon is also a good source of vitamin D. But your best bet might be a supplement. Little said, “I usually don’t recommend supplements, but for this situation we probably need one thousand IU’s per day.”

A vitamin D supplement will replenish what your body uses and loses in the winter. And little says nearly every Iowan needs more. Studies show three out of four of us are vitamin D deficient in February.

Little says a supplement should not replace vitamin D rich foods. The pills should be considered an addition to your diet.

Email Steve Nicoles at Steve.Nicoles@kcrg.com

NEW RESEARCH

A study from Harvard Medical School shows an increased risk of heart disease for those with low levels of vitamin D, and this risk is particularly high for those who also have high blood pressure.

- The U.S. study, which began in 1996, used over 1,700 people with an average age of 59. Continue Reading…