Vitamins & Supplements Archive

Q. I like smoked salmon and kippered herring, and thought that eating them was good for me. But I read in another health newsletter that the smoking process destroys all the heart-healthy omega-3 fats. Is that true?

A. I thought your question would be an easy one to answer. That didn't turn out to be the case. But with help from Heart Letter editor P.J. Skerrett, I think we can give you a solid answer.

It may be okay for prevention. But eating fish is a better strategy than gulping pills.

Fish oil has been flying high as a supplement for the past few years. It has garnered a reputation as an easy way to protect the heart, ease inflammation, improve mental health, and lengthen life. Such claims are one reason why Americans spend more than $1 billion a year on over-the-counter fish oil, and why food companies are adding it to milk, yogurt, cereal, chocolate, cookies, juice, and hundreds of other foods.

New dietary standards are more cautious than many expected.

After a decade of glowing reports for vitamin D, a panel of experts has seemingly thrown the dimmer switch on the sunshine vitamin. In revising the 1997 dietary guidelines, a panel convened by the Institute of Medicine (IOM) concluded that there wasn't enough solid evidence to support taking vitamin D to stave off a host of disorders from colon, breast, and prostate cancer to heart disease, arthritis, and autoimmune conditions. The panel's report, released on Nov. 30, 2010, also throws cold water on the assumption that most North Americans are deficient in vitamin D. The new recommended intake of the vitamin is higher, but not nearly to the level some advocates had anticipated and called for.

Food, and maybe a multivitamin, should provide all the Mg you need.

Magnesium deficits have been linked with a long list of cardiovascular and other disorders: high blood pressure, heart rhythm problems such as atrial fibrillation, cholesterol-clogged coronary arteries, painful spasms of coronary arteries, sudden cardiac arrest, diabetes, osteoporosis, and more. But whether modestly low magnesium stores are the cause of these conditions or the result of them is up in the air.

In recent years, many studies have suggested that we take much more vitamin D than we do now — especially those of us living in northern climes who may get too little sunlight to produce adequate amounts in the skin. Many scientists have advocated vitamin D doses of 1,000 to 2,000 international units (IU) a day — much higher than the present recommended dose — to prevent a host of chronic conditions. But the report of an expert panel convened by the Institute of Medicine (IOM) concluded in November 2010 that high doses of vitamin D aren't necessary and might even be harmful. Many people — including many clinicians and researchers — were taken by surprise.

The IOM panel, which included Harvard Women's Health Watch advisory board member Dr. JoAnn Manson, reviewed nearly 1,000 studies, representing more than 15 years of scientific findings. The panel decided that vitamin D's importance for bone building and the prevention of bone disease was well substantiated, but the evidence for its role in preventing other conditions was inadequate to justify its use at much higher doses. Thus, the Recommended Dietary Allowance (RDA) for vitamin D was set on the basis of bone health alone: 600 IU a day for everyone through age 70 and 800 IU a day for those 71 and older. (In setting these standards, the panel assumed no access to vitamin D through sun exposure.)

Q. What do you know about taking extra folic acid to boost the immune system?

A. Folic acid is the synthetic form of folate, a B vitamin that occurs naturally in some foods, including vegetables, fruits, and dried beans and peas — and is essential for health. Folate is vital for the production and maintenance of our bodies' cells, especially during rapid periods of growth, such as pregnancy and infancy. It's needed to make DNA and RNA, the genetic material that dictates cell functions, and it helps prevent changes to DNA that may lead to cancer.

Numerous studies have identified a correlation between higher consumption of the omega-3 fats contained in fish and fish oil and a lower risk of dementia and cognitive decline. Dig a little deeper, and one of the two main omega-3s, docosahexaenoic acid (DHA), seems to deserve most of the credit. Donepezil (Aricept) and other cholinesterase inhibitors are the most common treatment for mild to moderate Alzheimer's disease. But, at best, they somewhat slow down the pace at which Alzheimer's gets worse, and the side effects are a problem. With the lack of effective treatment and DHA's promise — and low cost — a study to see if the omega-3 might benefit people in the early stages of Alzheimer's disease would seem worth a try.

The Alzheimer's Disease Cooperative Study (ADCS), a consortium of Alzheimer's disease clinics with funding from the federal government to run clinical trials, conducted a high-quality (randomized, double-blinded, placebo-controlled) trial of DHA. About 400 patients with mild-to-moderate Alzheimer's were assigned to take either 2 grams of DHA derived from algae or a placebo pill every day for 18 months. (Algae-derived DHA is becoming popular because of concerns about overfishing and contamination with pollutants and the growing number of people adhering to vegan diets.) The study participants took a battery of tests to measure attention, language, and other cognitive abilities at the beginning and end of the study.

The body needs the combination of potassium and sodium to produce energy and regulate kidney function, but most people get far too much sodium and not enough potassium.

I'm 79 years old and have been taking 3,000 mg of vitamin C a day for years. I'm now uneasy about taking this amount and plan to cut back to 1,000 mg daily. Is this the right dose? Will my body be startled by the abrupt change?