Vitamin D – hormone and vitamin – assist in the regulation of calcium and phosphate levels in the blood, and essential in the development of strong bones and teeth. Although vitamin D can be obtained via oily fish and eggs, the adequate requirement is usually fulfilled through exposure to ultraviolet rays that help manufacture vitamin D in the body.

Now, a rather new benefit of this vitamin has been discovered. According to a preliminary study presented today at the Society for Endocrinology annual conference in Edinburgh, vitamin D supplements can enhance exercise performance and reduce the risk of heart disease.

Previous Studies On The Issue

About 10 million individuals in England might have low vitamin D levels. On average, one in every 10 adults has low levels of vitamin D during the summer, as compared to two in every 10 in the winter. People with darker skin are more prone to experience a deficiency of vitamin D in the winter – every three out of four adults – since darker skin is less effective in absorbing sunlight to produce the vitamin.

Previous studies have demonstrated that vitamin D blocks the action of 11-βHSD1, an enzyme needed to manufacture the ‘stress hormone’ cortisol. Elevated levels of this hormone might increase blood pressure via vasoconstriction, restricting arteries and stimulating the kidneys to retain water. Theoretically, by blocking this enzyme, vitamin D could improve exercise performance and reduce cardiovascular risk factors.

The Present Study

In a two week study, researchers from Queen Margaret University in Edinburgh administered 50μg of vitamin D or a placebo every day to 13 healthy adults matched by weight and age.

Results showed that supplementing adults with vitamin D reduced their blood pressure and lowered the levels of cortisol in their urine. A fitness test revealed that the group taking vitamin D supplements could cycle 6.5km in 20 minutes with reduced stress, as opposed to the placebo group that could just do 5km at the beginning of the study.

Drawing A Conclusion

“This pilot study suggests that vitamin D supplements can significantly improve fitness levels and reduce cardiovascular risk factors, including blood pressure”, stated co-author Dr Raquel Revuelta Iniesta. “The next step will be to perform a larger clinical trial over a longer period of time which includes both healthy individuals and large groups of athletes, such as cyclists or long-distance runners”.

“Vitamin D deficiency is a silent syndrome associated with insulin resistance, diabetes, rheumatoid arthritis, and an increased risk for certain types of cancers”, explained lead author Dr Emad Al-Dujaili. “Our study shows the importance of dealing with this widespread problem”.