Vitamins & Supplements Archive


Should I take vitamin D?

Ask the doctor

Q . I am 68 and in excellent health. I eat a healthy diet, exercise every day, and do not drink or smoke. I'm on no medicines. The only pill I take is vitamin D. But I'm wondering: is there any benefit in that?

A. In a nutshell, here's what we know. Our skin makes most of the vitamin D in our bodies after exposure to sunlight. Because most of us are indoors most of the 24 hour day, many of us have relatively low blood levels of vitamin D.

Dietary supplements can be hard to swallow

In the Journals

A study in The New England Journal of Medicine casts light on a little-known hazard associated with America's multibillion-dollar dietary supplement habit: difficulty swallowing among older people who take vitamin and mineral supplements—particularly calcium supplements.

Using a decade of records from 63 hospitals, researchers with the CDC and FDA estimated that 23,000 Americans end up in the emergency room because of bad reactions to dietary supplements. This includes herbal supplements and those containing vitamins, minerals, and other nutrients (such as amino acids).

Yohimbe supplements found to be dangerously strong

Image: Bigstock

In the journals

Dietary supplements containing the herbal ingredient yohimbe often contain prescription-strength active ingredients that are potentially dangerous, according to a study in Drug Testing and Analysis.

Scientists analyzed 49 popular brands of supplements with yohimbe. They found evidence that 39% of the products tested appeared to contain a pharmaceutical-grade extract of the herb.

Survey finds wide use of compounded postmenopausal hormones

Research we're watching

A national survey published Sept. 30, 2015, in Menopause indicates almost a third of women who take hormones at menopause are using compounded hormones—estrogen, progesterone, or testosterone prepared by a pharmacist according to a prescription. Such preparations aren't FDA-approved.

The survey, conducted by the North American Menopause Society, asked 3,700 women ages 40 to 84 about their hormone use at menopause. They were queried about the benefits they expected, the benefits they actually received, the side effects they experienced, and their health histories.

Research we're watching: Small study shows little bone benefit from recommended dose of vitamin D

Although vitamin D is essential to bone health, a controlled clinical trial published online by JAMA Internal Medicine on Aug. 3, 2015, found that vitamin D supplements didn't build bone in postmenopausal women with blood levels of vitamin D below the 30-ng/mL threshold generally considered necessary for good health. Researchers at the University of Wisconsin randomly assigned 230 women to three groups: one got 800 IU of vitamin D daily and a placebo twice a month; one got a placebo daily and 50,000 IU of vitamin D twice a month; the third got placebos both daily and twice a month. The study lasted a year. The researchers found that neither dose of vitamin D had a significant effect on bone mass, falls, or fractures.

The Wisconsin study may not have used the right doses of vitamin D or lasted long enough to show an effect. One ongoing study, The Vitamin D and Omega-3 Trial (VITAL), is large enough to demonstrate even small-to-moderate benefits of vitamin D supplementation. VITAL is evaluating a 2,000-IU daily dose for five years in 26,000 women and men. The results are expected in 2017. Until then, it's still important to get the recommended daily dose of vitamin D: 600 IU for adults through age 70 and 800 IU for people ages 71 or older

Ask the doctor: Saw palmetto and prostate health

Q. Some of my friends take saw palmetto supplements to reduce urinary problems caused by an overgrown prostate, which I was recently diagnosed with. My friends swear by it, but is there any good evidence this stuff helps? Is saw palmetto safe?

A. The short answer is that we don't have great scientific evidence that taking saw palmetto truly reduces male urinary problems. On the other hand, it doesn't appear to cause major side effects either.

In the journals: Seniors get no brain boost from omega-3 supplements

A recent study in The Journal of the American Medical Association found that seniors got no mental boost from taking daily omega-3 fatty acid supplements and antioxidant vitamins for four years. On the other hand, that doesn't mean eating a nutritious diet throughout life doesn't promote healthy aging.

The clinical trial involved more than 3,500 people, average age 73. Researchers were primarily testing the ability of daily nutritional supplements to prevent vision loss from age-related macular degeneration (AMD), which damages the light-sensing retina in the back of the eye. Participants also had tests of their mental function every other year in addition to annual eye exams.

Ask the doctor: Should I take a vitamin E supplement?

Some studies have shown that taking vitamin E supplements may slow the progression of Alzheimer's disease and acute macular degeneration. 
Image: Thinkstock

Q. Are there any benefits to taking vitamin E supplements? Or any risks?

What you should know about magnesium

Image: Bigstock

You need magnesium for many tasks. It's involved in more than 300 chemical reactions in the body. Muscles need this mineral to contract; nerves need it to send and receive messages. It keeps your heart beating steadily and your immune system strong. Most people can get enough magnesium by eating foods such as green leafy vegetables, whole grains, beans, nuts, and fish.

Dr. Bruce Bistrian, chief of clinical nutrition at Beth Israel Deaconess Medical Center and professor of medicine at Harvard Medical School, says magnesium deficiency in otherwise healthy individuals eating a balanced diet is rare. "The kidney has an extraordinary ability to reduce magnesium loss in urine, and thus achieve magnesium balance on a wide variety of intakes," he explains.

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