Vitamin Information Center

Next time you visit your local chemist, pause in the aisle containing vitamin supplements, and take in the quantities and varieties of pills and potions on offer. Tiny boxes and bottles stretch as far as the eye can see, affirming that even in these cash-strapped times, the gorging of such “miracle cures” continues to be big business.

But as the UK population continues to shell out millions annually on vitamin supplements, the scientific evidence supporting their efficacy is waning. Earlier this month, US scientists discovered that taking vitamins A and E does not lower your risk of cancer, one of the supposed major benefits of taking them.

“There have been a number of previous studies that have suggested that vitamin E and vitamin C might be important in the prevention of cancer,” says Dr Howard Sesso, one of those involved in the recent research. “The lack of an effect that we observe for vitamin E or C on cancer does convince us that these particular doses that we tested really have no role for recommendation for cancer prevention,” continues the academic. The clinical trials he oversaw involved nearly 15,000 American men.

Another recent study, part-funded by German chemicals firm BASF, whose products include vitamins, working in association with Brigham and Women’s Hospital, Boston, discovered that there were no significant effects on rates of heart disease after taking vitamins E and C. Two months ago, a major trial studying whether vitamin E and selenium (which, among other things, helps regulate hormone metabolism in the thyroid) could lower a man’s risk of prostate cancer ended amid worries that such treatments may do more harm than good. As if that were not enough, doctors at New York’s Memorial Sloan-Kettering Cancer Centre have warned that vitamin C seems to protect not only healthy cells, but cancer cells, too.

So should we be taking vitamin supplements at all? “We say that people don’t need to take vitamin supplements to have a healthy balanced diet. The only situation in which you should have to take vitamin supplements is if you are elderly or suffering from a long-term illness. People should address whether they have a healthy diet rather than seeing vitamins as a complete solution,” says Heather Caswell, nutrition scientist at the British Nutrition Foundation.

“People get a lot of vitamins from food,” adds health expert and author Oliver Gillie. “The exception is, of course, if you have too many things in your diet that are vitamin-depleted because they are totally refined. This includes cake and biscuits, which have large amounts of refined starches in them. On the other hand, if you are eating brown bread and you are consuming lots of vegetables, and a certain amount of meat and eggs, you will be OK.”

If the evidence against supplements is rapidly becoming insurmountable, why do people keep taking them? Well, some supplements still have proven advantages for people’s health. Vitamins such as B12 – that are good for facilitating normal functioning of the brain and nervous system – are still believed by some to have benefits for women of child-bearing age and the elderly. Furthermore, calcium and vitamin D in women over 65 appear to protect the health of the bones of those taking them.

People seem to experience the placebo effect more than ever with vitamins – thinking that the more they spend, the more they are able to stave off the worst effects of disease and age. The general belief is that they boost the body’s ability to mop up cancer-and-heart-disease-causing free radicals.

In some cases, in the UK at least, there is increasing evidence that some vitamins do have benefits. “Vitamin D is different,” adds Gillie. “A healthy person normally gets 90 per cent of the vitamin D they need from the sun. Unless you are an Eskimo or a Scottish fisherman living 100 years ago where you ate fish every day, then you can’t get enough from your diet.” A lack of vitamin D has been linked to increased rates of cancer, high blood pressure, osteoporosis, depression and schizophrenia.

Today, top Scottish doctors are meeting to discuss how to deal with the fact that, due to the country’s northerly location and consequent lack of sunlight, large swathes of its population are not getting enough of the vitamin, which is believed to support the healthy operation of organs.

“I am going to a conference in Edinburgh called by Scotland’s chief medical officer, Dr Harry Burns, who is concerned with the low levels of vitamin D in the Scottish population. It is an extreme case in the industrial world. In places like Glasgow there is so little ultraviolet light that people are in drastic need of vitamins. They are in an extreme situation because of their maritime climate. Scotland has got more cases of multiple sclerosis [which is believed to be naturally inhibited by vitamin D] than any other country in the world.”

But there’s now increasing evidence that taking too much of some vitamins can cause harm to people’s health. Recent studies – one by the Johns Hopkins School of Medicine – have shown that taking large amounts of vitamin E with other vitamins results in a 6 per cent higher risk of premature death. Another study, reported in the Journal of Clinical Oncology, of 540 patients showed that cancer recurrence rates were higher among vitamin users than among non-users. There seems to be increasing evidence that the death knell for certain vitamin supplements has now well and truly been sounded. Could it be time to step out of the chemist’s and back into the kitchen?

Complete meals: How to get your daily dose

Vitamin A

Liver, full-fat dairy products, spinach, broccoli, tomato juice, peppers and watercress. Orange things, such as mango, dried apricots, butternut squash, carrots, sweet potatoes and pumpkin tend to be good sources of this vitamin.

Vitamin D

Oily fish (salmon, sardines, pilchards, tuna, mackerel, trout or herring), dairy products and eggs. Also exposure to sunlight.

Vitamin E

Broccoli, nuts, soya beans, brussels sprouts, spinach and eggs. Some believe vitamin E is destroyed by heat, so try to eat your vegetables raw or lightly cooked.

Vitamin C

Citrus fruits and juices, kiwi fruit, strawberries, blueberries, tomatoes and peppers.

Vitamin B

Vitamin B1 is found in whole grains, flour and bread and green leafy vegetables; Vitamin B2 is found in eggs, liver, milk, and cheese; B3 is in protein-rich foods like meat, liver and peanuts; B5 is in chicken, eggs, beef and broccoli;

B6 is in fish, chicken and wholegrain cereals; B9 is in raw fruit as well as yeast and liver and B12 is in fish, dairy produce, meat and yeast extract.

Abundant dietary vitamin C may lower the risk of developing type 2 diabetes, say researchers from the Institute of Metabolic Science at Addenbrooke’s Hospital in Cambridge, England.

Scientists there followed 21,831 men and women aged 40 to 75 over a 12-year period, during which they tracked diet, exercise, and blood content. By the end of the study, 423 men and 312 women-3.2 percent of the study group-had developed type 2.

The researchers concluded that the subjects with the highest levels of vitamin C in their blood were 62 percent less likely to develop type 2 than the subjects with lower levels.

Fruit and vegetables were the subjects’ main sources of vitamin C. The researchers said that other factors commonly associated with a risk for diabetes, such as age, sex, smoking, family history, weight, and alcohol consumption, did not significantly alter the beneficial effects of vitamin C.

Is Gum Disease a Precursor to Diabetes?

If you have gum disease, your chances of developing type 2 diabetes are nearly double those of people who don’t have gum disease, according to researchers at Columbia University’s Mailman School of Public Health in New York City.

That was their conclusion after a 20-year study that tracked 9,000 people without diabetes.

The presence of periodontal disease has often been noted as an accompaniment to diabetes, but nobody is sure whether it is a precursor to the disease or possibly even a contributing factor.

Because gum disease, like diabetes, involves tissue inflammation, there is some speculation that it is an indicator of susceptibility to inflammatory disease.

Thirty-five percent of adults have some form of gum disease, and one third of those experience a troubling level of infection.

Researchers don’t know what causes periodontal disease. Theories include genetics, smoking, and dry mouth caused by medications. Treatments include antibiotics, topical gels, extremely deep tooth cleaning, and even surgery to graft tissue from the roof of the mouth onto affected spots to encourage new gum growth.

The hope is that lowering the level of inflammation in the mouth may decrease the likelihood of inflammation developing elsewhere in the body.

Source: Diabetes Care, July 2008

Launched a decade ago, the federal program requiring folic acid to be added to widely consumed foods has been hailed as one of the great public-health success stories. Harnessing a seemingly harmless vitamin, it helped slash the number of babies born with spina bifida and other devastating “neural-tube” defects.

But scientists are beginning to debate whether Canadians’ growing consumption of the nutrient may also be taking a terrible, unplanned toll, triggering hundreds of extra cancers annually, even as it makes pregnancies safer.

One Canadian specialist says the federal government should now consider abandoning fortification altogether, and focus folic-acid efforts more narrowly on the young women who unquestionably benefit from the vitamin.

“It’s a double-edged sword,” said Young-In Kim, a gastroenterologist and folic-acid researcher at the University of Toronto.

“It was meant to prevent neural-tube defects, and it did a wonderful job. [But] for people with pre-cancerous cells, or undiagnosed colon cancer tumours, giving high-dose folic acid or having high folate levels might actually make their condition worse.”

Other experts, though, argue that fortifying food offers well-proven health advantages, while evidence of any cancer risk is inconclusive at best. In fact, the Society of Obstetricians and Gynecologists of Canada has advocated higher intake of folic acid supplements for some women, while the March of Dimes and American Medical Association in the United States have called for doubling the level of folic acid - or folate - that must be added to flours and other raw grains.

“You need more substance to show harm [from folate fortification], and there has been a clear absence of substance,” said Dr. Joel Ray, a scientist at St. Michael’s Hospital in Toronto who has studied folic acid. “We shouldn’t backtrack and change the direction of the program right now.”

Health Canada has reviewed what it calls the “inconsistent” evidence on the issue, and has no plans to alter or cancel the program, said Alastair Sinclair, a department spokesman.

“It is not possible to conclude that fortification has increased the rates of colorectal cancer incidence in Canada,” he said.

The folic-acid story revolves around birth defects, specifically those where the fetus’s neural tube, which becomes the brain and spinal cord, develops improperly, sometimes resulting in major disabilities. Folic acid seems to have a powerful preventive effect. A 2007 study concluded that rates of spina bifida and other neural-tube defects fell by about 50% - or about 110 babies a year - in the wake of the fortification program.

Adding the vitamin to food started on a voluntary basis in this country in 1996, and became mandatory for white flour, enriched pasta and cornmeal in late 1998. Evidence had shown that many women of child-bearing age did not heed expert advice to take folic acid pills, which have limited effect if started after a woman becomes pregnant.

The target was younger women, but the fortification program, following on the heels of one in the U.S., led to a doubling on average in the level of folic acid in all Canadians. Some experts suggest that is not a bad thing: There is evidence that it actually protects people against certain cancers.

Two hotly contested studies published last year, however, have fuelled concerns that elevated levels in North American bloodstreams may be having the opposite effect. A trial published in The New England Journal of Medicine had been designed to test whether folic acid prevented pre-cancerous colorectal polyps. In fact, it found that those subjects taking folate supplements were slightly more likely to have multiple polyps and to develop prostate cancer.

Animal studies, meanwhile, have suggested that the vitamin can prevent colorectal cancer in healthy individuals, but can also make it more likely that pre-cancerous polyps will convert into malignancies and that existing cancers will develop faster.

Then there is the history of folate. In the 1940s, physicians experimented with giving it to children suffering from leukemia, only to find that it accelerated the disease. That discovery led to the development of the first chemotherapy drugs - ones that actually countered the effects of natural folate, said Kim.

He was among the experts consulted by U.K. officials recently as they considered implementing fortification. The British decided last year to put the plan on hold.

Another 2007 study, meanwhile, noted that colorectal cancer rates rose suddenly in both Canada and the U.S. in the years after folic acid fortification started, and suggested there could be a link. The rates here climbed to almost five extra cases per 100,000 annually, before sliding back to a level that was still somewhat higher than before fortification.

That means that as many as 1,500 additional Canadians were diagnosed with colorectal cancer yearly after folate levels started to soar.

Dr. Joel Mason of Tufts University in Boston, who spearheaded the study, said there is not yet enough evidence to justify actually cancelling the fortification program, but called for more research on the possible cancer connection. He also suggests that anyone who is not a woman in her reproductive years think twice about taking folic acid supplements, which only add to the levels provided by fortification.

“We don’t know whether taking vitamin supplements and fortifying food [with folic acid] … actually accelerates cancer risk among susceptible people, but there is certainly a scientific basis for that possibility,” Mason said.

“We can’t afford to ignore it. It’s not a trivial phenomenon.”

Yet his and the New England Journal study have both come under stiff criticism.

British experts on spina- bifida argued in a letter to The Lancet last year that the trial published in the New England Journal showed no significant evidence that folate can be carcinogenic. And, like Ray, they said the increased cancer rates identified in Mason’s study were likely just a result of stepped-up screening for colorectal cancer.

In the meantime, a study published last month in the World Journal of Gastroenterology offered a much rosier view of the vitamin. It found that after three years, patients who took folic acid supplements actually had a third as many of the polyps that can lead to colorectal cancer as those taking a placebo.

Having too little vitamin D in the body might raise the risk of premature death, a study by Johns Hopkins researchers shows.

It follows other recent studies showing that low amounts of vitamin D are linked to certain cancers, diabetes, and bone and immune system problems, but this is the first research to connect vitamin D deficiency to a higher risk of death, said the study’s co- author Erin Michos, an assistant professor of cardiology at Johns Hopkins School of Medicine in Baltimore.

The study appears in this week’s Archives of Internal Medicine.

Michos and her colleagues analyzed data from a large government observational survey of more than 13,000 people who represented a realistic, diverse swath of U.S. adults ages 20 or older. Participants’ vitamin D amounts were determined through blood tests from 1988 through 1994.

By 2000, Michos said, 1,807 deaths had occurred, including 777 from cardiovascular disease.

The researchers divided the total population into four groups based on their amounts of vitamin D. One group included people with the least vitamin D, 17.8 ng/mL (nanograms/milliliter) or less.

A normal vitamin D test result for both children and adults is 30 ng/mL or more. Less than 20 ng/mL is considered deficient, and results between 20 and 30 ng/mL are labeled insufficient, said Catherine Gordon, director of the bone health program at Children’s Hospital Boston.

In the study, Michos said, people who had low vitamin D — 17.8 ng/mL or less — were 26 percent more likely to be dead at the end of the study than those with more.

Michos now suspects that low vitamin D is related to heart disease deaths, but that theory has to be tested in further studies, she said.

Originally published by USA TODAY.

(c) 2008 Tulsa World. Provided by ProQuest LLC. All rights Reserved.

Source: Tulsa World

CHRONIC pain in women may be related to low levels of vitamin D, the nutrient made by the skin when exposed to sunlight.

Researchers who studied nearly 7000 British 45-year-olds found that almost 15 per cent of women with the lowest levels of the vitamin reported experiencing chronic pain - nearly twice the 8.2 per cent prevalence reported among women with higher readings.

However, vitamin D levels appeared to make no difference to the number of men who reported pain symptoms - leaving the study’s authors perplexed as to whether lack of vitamin D in women was the cause.

The authors noted that a disease caused by extreme vitamin D deficiency, osteomalacia, was known to cause bone pain.

The research concluded that further studies were required to establish whether pain would be lessened if patients increased their vitamin D intake.

For the study, published yesterday in the journal Annals of the Rheumatic Diseases, the authors included medical data from 6824 Britons who were examined between 2002 and 2004, when they were aged 45. Information was collected on their smoking and alcohol habits, time spent outdoors, time spent watching television or at a computer and dietary supplements, including vitamin D.

Samples of their blood werealso analysed for

levels of 25-hydroxy-vitaminD (25(OH)D), which is a metabolised form of the vitamin and a marker for vitamin D levels.

The lowest prevalence of chronic widespread pain (8.2per cent) was reported in women with 75 to 99 nanomoles of 25(OH)D per litre of blood.

The rate was 14.4 per cent for women with less than 25nmol/l, and 14.8per cent for women with 25-49nmol/l.

John Eisman, director of the bone and mineral research program at the Garvan Institute of Medical Research, said the study was interesting but by its design could not “unravel” whether lower vitamin D was causing the pain, or vice-versa.

Professor Eisman, who is also an endocrinologist at Sydney’s St Vincent’s Hospital, agreed that more studies were required.

In the meantime, if doctors were faced with patients battling chronic pain, “it might be worth giving them vitamin D, to see if it makes a difference”, he said.

An abundance of vitamin C in the diet may help lower a person’s risk of developing type 2 diabetes, new research suggests.

In a study of middle-aged and older men and women, those with the highest blood levels of vitamin C were significantly less likely to develop diabetes over 12 years than those with the lowest levels, researchers found.

Fruits and vegetables are the main source of vitamin C in Western diets, and blood levels of vitamin C are good markers of fruit and vegetable intake, Dr. Nita G. Forouhi, at the Institute of Metabolic Science at Addenbrooke’s Hospital, Cambridge, England, and colleagues note.

The current findings “re-endorse the public health message of the beneficial effect of increasing total fruit and vegetable intake,” the investigators wrote in Archives of Internal Medicine.

Forouhi’s team followed 21,831 healthy men and women who were 40 to 75 years old for the development of type 2 diabetes. At study entry, all participants provided detailed health and lifestyle information, as well as blood samples, which investigators used to determine vitamin C levels.

Over the course of the study, 423 men and 312 women developed type 2 diabetes, an overall rate of 3.2 percent.

According to the investigators, the likelihood of developing diabetes was 62 percent lower in men and women with the highest circulating vitamin C levels, relative to men and women with the lowest vitamin C levels.

Factoring out other characteristics associated with diabetes risk, such as older age, gender, family history, alcohol intake, physical activity, smoking status and body weight did not significantly alter these associations.

These data offer “persuasive evidence of a beneficial effect of vitamin C and fruit and vegetable intake on diabetes risk,” Forouhi and colleagues conclude.

Yes - a blood test called 25-hydroxyvitamin D, which, though expensive ($20 to $100 a pop), is covered by insurance. Your level should be at least 30 nanograms per milliliter of blood and not more than 100. If your level is way below that, say around 18, you need to take 1,200 international units or more a day of vitamin D supplements, either the type called D2 or D3, said Dr. Michael F. Holick, an endocrinologist and leading vitamin D researcher at the Boston University School of Medicine. Continue Reading…