Research suggests that higher doses of the sunshine vitamin may be good for your health, but it's too soon to be sure.

Vitamin D is needed to maintain strong bones. A flood of recent studies have also hinted that vitamin D may help to prevent a wide variety of health problems—including some of great interest to men, like heart disease and cancer. You clearly need some vitamin D to be healthy but should
you take more?

You've heard all the warnings about dietary supplements. Here are a few that men should use with caution or avoid.

Americans spend more than $32 billion on 85,000 different dietary supplements every year. These products contain various combinations of vitamins, minerals, herbal extracts, and other substances. The manufacturers claim that their products enhance health, but the scientific evidence ranges from slim to none in most cases. People still perceive dietary supplements as inherently harmless, but that's not always true.

Taking a daily calcium and vitamin D supplement lowered LDL (bad) cholesterol levels and increased HDL (good) cholesterol in postmenopausal women.

Your body depends on the mineral potassium for many bodily functions, including keeping control of the electrical balance of your heart, metabolizing carbohydrates, and building muscle.

Low potassium levels can cause muscle weakness and heartbeat irregularities. On the other hand, too much potassium can cause your heart to stop.

Taking extra vitamin E or selenium every day can raise the risk of prostate cancer, according to a study published online February 22 in the Journal of the National Cancer Institute.

The findings confirm what researchers have suspected since the first results emerged in 2008 from the Selenium and Vitamin E Cancer Prevention Trial
(SELECT). Researchers halted SELECT early after finding no evidence that taking a daily supplement—with 200 micrograms (mcg) of selenium, 400 international units (IU) of vitamin E, or both—reduced the risk of prostate cancer. The early results also suggested that taking vitamin E increased the chance of prostate cancer by 17%.

Taking a multivitamin does not reduce the chance of heart disease or mental decline, but it does reduce the risk of being diagnosed with cancer or developing cataracts.

In brief

B vitamins and homocysteine

A high homocysteine level is not something you want to have. Homocysteine is an amino acid in the blood, and elevated levels have been linked to dementia, heart disease, stroke, and osteoporosis. The good news: Homocysteine can be lowered easily and inexpensively with a trio of B vitamins — B6, B12, and folic acid.

Problem solved? Not so fast. Lowering homocysteine doesn't mean much unless those reduced levels translate into reduced risk for the problems that elevated levels are thought to cause. Otherwise, you're just treating a blood test.

A recent review casts doubt on supplements for disease prevention. Are they still worth taking?

Following the news on supplements is a little like trying to keep up with a fast-paced game of ping-pong. One study finds supplements improve health, and then another questions the benefit of taking them. Back and forth they go.