Vitamins & Supplements Archive

Q. Is there any medication or over-the-counter supplement or vitamin I can take to prevent dementia?

A. Unfortunately, no drug, supplement, or vitamin can prevent you from getting dementia. The 2010 Consensus and State-of-the Science Statement on Preventing Alzheimer's Disease and Cognitive Decline from the National Institutes of Health reviewed all the available scientific evidence on the topic. The authors concluded, "Evidence is insufficient to support the use of pharmaceutical agents or dietary supplements to prevent cognitive decline or Alzheimer's disease." So there are currently no good scientific data to show that taking anything—whether it's ginkgo biloba, vitamin E, or donepezil (Aricept)—will protect you from losing mental function.

Q. A friend told me she takes magnesium pills every day. Does this improve your health?

A. Most people get all the magnesium they need from a normal diet. However, there are several diseases and treatments that can cause magnesium deficiency: Crohn's disease (an inflammatory condition of the intestine), celiac disease, inadequately treated diabetes, alcohol abuse, gastric bypass surgery, and diuretic medicines. People with these conditions or treatments should have their blood levels of magnesium checked periodically. If those levels are low, they should consider taking magnesium pills or eating lots of foods rich in magnesium: nuts, fish, certain fruits, many vegetables, and whole grains.

Q. I had a heart attack 20 years ago. My doctor told me to stop taking vitamin E. My old cardiologist told me to take vitamin E every day to prevent another heart attack. What should I do?

A. Vitamin E is an antioxidant found in fruits and vegetables. Vitamin E supplements were once thought to boost antioxidant levels and fight off disease.

Does taking vitamin D supplements prevent heart disease?

Studies conducted mainly in white people suggest that it might. But now a carefully controlled study finds that while low vitamin D blood levels are linked to heart disease in white Americans, the same is not true for black Americans.

Lower vitamin D levels have been proposed as one reason for black Americans' higher risk of heart disease relative to whites. But the report, in the Journal of the American Medical Association, indicates this is not the case. A research team led by Dr. Ian de Boer of the University of Washington measured vitamin D levels in 6,364 adults and followed them for 8.5 years.

While there’s good evidence that omega-3s in the diet offer protection against heart disease and stroke, omega-3 fatty acids found in fish oil supplements may not reduce the risk of stroke or heart attack among people with a high heart disease risk.

Men who consume the most vitamin E are at increased risk for heart failure, while those with the highest vitamin C levels have a lower heart failure risk, finds an 11-year study of men ages 60 to 79.

S. Goyha Wannamethee of University College London led the study, which followed nearly 4,000 men. In men who had a previous heart attack, high vitamin E consumption increased risk of heart failure by 23%.

Calcium is most effective when it comes from the food you eat. Use our guide to identify convenient sources.

Many people take daily calcium supplement pills. However, two studies published in February 2013 add to the concern that regular use of high-dose calcium supplements may increase the risk of heart disease.

It's easy enough to look up how much vitamin C or calcium you should get each day. It is also easy to read the back of a vitamin bottle to see just how much of a given vitamin or mineral the product provides. But how can you tell if what you eat — which should be your primary source of important nutrients — is giving you what you need?

One way is to focus on the big picture: eat a balanced diet that contains a variety of colorful fruits and vegetables, whole grains, beans, nuts, dairy products, seafood, lean meats, and poultry. Focus on nutrient-dense foods like these, which are packed with vitamins and minerals relative to the number of calories they deliver, and you should be fine.

Getting too much calcium, particularly by adding supplements to calcium in your diet, could be risky, according to a study published in the February BMJ. Researchers in Sweden followed a group of more than 61,000 women for two decades. The women filled out dietary questionnaires, and based on their responses, the researchers assessed how much calcium the participants got from diet and supplements. Women who took more than 1,400 milligrams (mg) of calcium per day from diet and supplements were at higher risk of death from all causes, cardiovascular disease, and ischemic heart disease (when the heart muscle doesn't get enough oxygen). The increase in risk for women who consumed 1,400 mg of calcium from diet alone was more moderate. This study relied on women's recollections of their diet, which means that their reporting might not be 100% accurate. Still, this is one of several studies to find a connection between high doses of calcium from supplements and an increased risk of death in both men and women. To shore up your bones and prevent fractures, health experts recommend getting 1,200 mg of calcium a day. However, the U.S. Preventive Services Task Force (USPSTF) does not recommend that postmenopausal women take daily calcium supplements for fracture prevention. The safest sources are foods such as low-fat milk, yogurt, sardines, and salmon.

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