A growing number of medical experts are concerned that we are overdoing our vitamin consumption. Too many people are taking supplements, mostly vitamins, convinced that the pills will make them healthier.
But researchers say that vitamin supplements cannot correct for a poor diet, that multivitamins have not been shown to prevent any disease and that it is easy to reach high enough doses of certain vitamins and minerals to actually increase the risk of disease.
We are no longer concerned about vitamin deficits. Those are almost unheard of today, even with the population eating less than ideal diets and skimping on fruits and vegetables. Instead, the concern is with the dangers of vitamin excess.
Some supplements, including vitamin A, the difference between the recommended dose and a dose that could lead to bad outcomes like osteoporosis was not large. Popular multivitamins, he added, often contain what could be risky doses.
Doctors who once told patients that multivitamins were, at worst, a waste of money now say they are questioning that idea.
With vitamin A in particular, it is easy to step over the edge into a danger zone. You can be eating Total cereal, drinking fortified milk, taking a multivitamin. You can get into a situation where you're getting more than you need. Until recently, there was little concern about vitamin A and bone health."
Similar questions are being raised about other vitamins and minerals, notably iron and vitamins E and C.
Researchers say the questions involve multivitamins taken by healthy people, not specific vitamins or minerals taken by groups with specific needs. Some elderly people, for example, may be deficient in vitamin B12 because they lose their ability to absorb it from foods. People who spend little time outdoors may require vitamin D, which the skin makes when it is exposed to sunlight. Even when older people are in the sun, aging skin loses much of its ability to synthesize the vitamin.
Pregnant women who do not receive enough folic acid, a vitamin in fruits and vegetables that are added to enriched flour are at increased risk of having babies with neural tube defects. Because the vitamin is needed at the very start of pregnancy, some advocate folic acid supplements for all who might become pregnant, just to be sure they are protected.
For most people, however, the issue is not deficits. Instead, nutrition researchers ask: Do people eating relatively healthy diets with fresh fruits and vegetables and not too many calories or fats benefit from multivitamins or other supplements? Do those whose diets are abysmal, heavy on fast foods and lacking in fruits and vegetables, make up for some deficits if they take multivitamin pills?
The most popular individual supplements are vitamins C and E. Scientists once thought those vitamins could help prevent ailments like cancer and heart disease, but rigorous studies found no such effects.
Vitamin E supplements can increase the risk of heart attacks and strokes, and studies of vitamin C supplements consistently failed to show that it had any beneficial effects.
The two vitamins that are the most not needed are the ones most often taken.
Excess vitamin C is excreted in the urine, but excesses of some other vitamins are stored in fat, where they can build up. Of particular concern, researchers say, is vitamin A. It is found in liver, and small amounts are added to milk. But for most people who are reaching worrisome levels, the main source is supplements, multivitamins, nutrition bars, health drinks and cereals.
Several recent large studies indicate that people with high levels of vitamin A in their blood have a greater risk for osteoporosis. People can easily reach a potentially dangerous level, about five times the recommended dose, by taking vitamins and supplements, nutrition researchers say. Some popular multivitamins run 1,500 micrograms a pill, twice the recommended daily amount and a level that, in one recent study, doubled the risk of bone fractures. Some supplements provide as much as 4,500 micrograms a day, well above the level that the National Academy of Sciences in the USA calls an upper limit for safety.
If you have a good source of vitamin A in your food and you take a supplement with another 100 percent, you can easily reach a level that can accumulate to one associated with increased risk of osteoporosis.
As far as iron is concerned it should be taken by all women between the ages of twenty and menopause as they lose blood with their monthly period and with the multiple pregnancies common in the Arab family.
However older people and men in general should not take iron without a documented case of anemia, the same is true with folic acid.
A European study, reported recently at a meeting of the American College of Cardiology, found that folic acid supplements actually made matters worse for heart disease patients. The study, the Folate After Coronary Intervention Trial, involved 626 patients who were having stents inserted into blocked arteries to keep them open. Half were randomly assigned to take folic acid, and the rest took a placebo. Six months later, the arteries of those taking folic acid were significantly narrower than the arteries of those taking a placebo, exactly the opposite of what the investigators had expected.
Some scientists recommend a compromise by taking a child's multivitamin, with its much lower levels of vitamins and minerals.
It is virtually impossible to find an adult multivitamin and mineral supplement that is only 100 percent of the R.D.A. (Recommended Daily Allowance). All are 150 percent or so. I worry about getting too much and I worry about imbalances. The manufacturers put in more of the things that are inexpensive, like B vitamins and things with consumer appeal like vitamin C. The formulas are based on market forces, not nutritional needs.
There is no disease that I know of that is prevented by multivitamins.
In fact, typical pills, which contain a variety of minerals as well as vitamins, have ingredients that actually cancel out one another. Minerals antagonize each other for absorption, Zinc competes with iron and iron competes with calcium.
Large, rigorous studies that were supposed to show that individual vitamins prevented disease ended up showing the opposite. Those who took the vitamins actually had more of the disease it was meant to prevent.
Two large randomized trials of vitamin A and beta carotene that researchers hoped would show a protective value against cancer found no benefit, and one found that participants who took the supplements had more cancer.
A large study of vitamin E and heart disease found that it did not prevent heart attacks and that people taking it had more strokes.
Another study, of women with heart disease, found that antioxidant vitamins might actually increase the rate of atherosclerosis.
People are deluding themselves if they thought multivitamins could make up for poor diets.
If you eat junk food every day, vitamins are the least of your problems. You cannot replace a healthy diet. We don't know what ingredient in a healthy diet is responsible for which condition. We do know that people who consume five servings or more of fruits and vegetables have less disease. But we don't know which ingredient. We tried beta carotene, vitamin E and antioxidants, and they didn't work.
People are looking for the magic bullet. It does not exist. They need to drink a lot of water and not juices, exercise, quit smoking and eat more fresh fruits and vegetables and less meat, fast food, fried food and junk food.
For more information call Dr. Max Mazen Sawaf, medical director at CosmeSurge Jumeirah Medical Center in Dubai or visit the website www.cosmesurge.com
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© Press Release 2006
