Heart and bone risk from low vitamin D

BALTIMORE, Nov. 18 (UPI) -- Long-term vitamin D deficiency may result in lower levels of the sex hormone estrogen but not testosterone, U.S. researchers said.

Lead investigator and cardiologist Dr. Erin Michos of The Johns Hopkins University School of Medicine said the findings build on previous studies showing that deficiencies in vitamin D and low levels of estrogen, found naturally in differing amounts in men and women, were independent risk factors for hardened and narrowed arteries and weakened bones.

"Our results confirm a long-suspected link and suggest that vitamin D supplements, which are already prescribed to treat osteoporosis, may also be useful in preventing heart disease," Michos said in a statement. "All three steroid hormones -- vitamin D, estrogen and testosterone -- are produced from cholesterol, whose blood levels are known to influence arterial and bone health."

The 1,010 men in the study had their hormone levels measured for both chemical forms of testosterone and estrogen found in blood. Initial results showed no link between vitamin D deficiency and depressed blood levels of either hormone.

However, when researchers compared ratios of estrogen to the protein sex hormone binding globulin levels, they found that rates of osteopenia, the early stage of osteoporosis, were higher when both estrogen and vitamin D levels were depressed. Men low in vitamin D were also at heightened risk of cardiovascular diseases compared to men with adequate levels of the vitamin.

The findings were presented at the American Heart Association's annual scientific sessions in Orlando, Fla.