Vitamin D, a fat-soluble vitamin, helps the body absorb and metabolize calcium and phosphorus. It is also involved in neuromuscular function. Sunlight synthesizes vitamin D in the skin and is obtained through diet. Evidence indicates that a low vitamin D level in men poses adverse effects on overall health.

Increases Cancer Risk

Low vitamin D might increase cancer incidence in men, according to lead author Dr. Edward Giovannucci and colleagues from Harvard School of Public Health. They examined the relationship between vitamin D status and cancer incidence for men in the Health Professional Follow-Up Study cohort. The report, published in the April 2006 issue of the “Journal of the National Cancer Institute,” revealed that men with insufficient vitamin D had an increased risk of developing cancer, especially digestive system cancers, compared to those with sufficient vitamin D.

Increases Heart Attack Risk

Inadequate vitamin D increases the risk for a heart attack in men. Giovannucci and researchers from Harvard School of Public Health found that men deficient in vitamin D presented a higher risk of myocardial infarction, also known as a heart attack, compared to those with sufficient vitamin D levels, the June 2008 issue of the journal “Archives of Internal Medicine."

Lowers Testosterone Levels

Lead author Elisabeth Wehr and fellow researchers from Medical University Graz in Austria studied the relationship between vitamin D status and testosterone levels in men referred for coronary angiography. The study, reported in the August 2010 issue of “Clinical Endocrinology,” revealed that men with inadequate vitamin D levels had lower levels of the hormone testosterone compared to those with adequate levels. Testosterone is crucial for maintaining muscle, as well as increasing libido.