So should you or shouldn't you be taking a multivitamin or any other vitamin or mineral supplements?
Research released Monday showed that older women who took a daily vitamin supplement, even just a multivitamin, had an increased risk of dying of cardiovascular disease and cancer. The link between supplement intake and risk of premature death was strongest with iron. Calcium supplements were associated with reduced risk.
Another study, out Tuesday, found that taking vitamin E supplements significantly increased the risk of prostate cancer in healthy men even after they stopped taking them. (Story, 3A.)
The findings highlight concerns about the long-term use of supplements and vitamins by people who do not have severe nutritional deficiencies. More than half of U.S. adults take vitamins or other dietary supplements
USA TODAY asked two top national nutrition experts to weigh in on whether consumers should take a multivitamin or other supplements.
Q: What is your take on the study about vitamins increasing the risk of death in older women?
Blumberg: This is a surprising outcome in one study. The results are contrary to other research. This new report says a multivitamin increases mortality, while other studies show that taking a multivitamin reduces or has no effect on total mortality.
Nestle: These are the latest findings to show potential harm in taking vitamin supplements at any level ranging from those in multivitamins to megadoses of individual supplements. The increase in risk is relatively small, although statistically significant. There has been one study after another showing that vitamin supplements either cause harm or do not do any good. It's hard for me to believe that multivitamins are harmful, but there's not much evidence that they do good.
Q: Do you recommend a multivitamin?
Blumberg: I do. Lots of people are falling short of the recommended daily amount of several nutrients including calcium, potassium, vitamin D and vitamin E. To make sure we are getting the recommended amount of those and other nutrients, I advise taking a multivitamin formulated at about 100% of the daily value.
Nestle: I much prefer food. I suggest supplements only to people with diagnosed nutrient deficiencies. One interesting finding in the (first) study is that women taking iron supplements had the highest risk. Why were women in their 80s taking iron supplements anyway? They are postmenopausal and do not have to replace iron lost during menstruation.
Q: Do you advise people to take other vitamin and mineral supplements?
Blumberg: It depends on who you are and what you eat. Because the calcium in a multivitamin is not even close to the daily value, I recommend an additional supplement of calcium for people who don't drink a lot of milk or eat enough dairy.
Because the recommended daily value of vitamin D was recently increased and this change is not reflected in most multivitamins on the market, I recommend that if you take a calcium supplement, you take one that also has vitamin D.
Beyond that, you need to think carefully about whether you need additional supplements. For example, if you don't eat much fish, have high triglycerides, and/or are at an increased risk for heart disease, you should consider a fish oil supplement of about one gram daily.
Nestle: Never. I think there are far too many studies now that suggest harm from excessive supplement intake. It's very difficult to induce clinically significant nutrient deficiencies in people who get enough calories and eat reasonably well.
Q: Do most people follow a diet healthful enough to get the nutrients they need?
Blumberg: The average diet is poor when it comes to meeting recommended intakes of vitamins and minerals. Only about 3% of Americans adhere to the dietary guidelines. How many Americans do you know who eat five to nine servings of fruits and vegetables a day and consume at least 50% of their grains as whole grains?
If you are eating a perfectly healthful diet, then you don't need supplements. But for the 97% who aren't there yet, for goodness' sake, take a multivitamin.
Nestle: Given our overabundant, over-fortified food supply, you would have to eat a highly restricted diet to develop (vitamin) deficiency symptoms.
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