Vitamin D supplements may improve exercise performance and lower the risk of heart disease. Researchers say that vitamin D can block the action of an enzyme called 11-ßHSD1, which assists in making the stress hormone cortisol. Elevated levels of this hormone can increase blood pressure by restricting the arteries, narrowing blood vessels, and encouraging the kidneys to retain water. Thus,...

Women who are deficient in vitamin D may be up to 6.7 times more likely to develop age-related macular degeneration (AMD) than women without who have healthy vitamin D levels. AMD is the leading cause of legal blindness, and it affects more than ten million Americans. The study's lead author, Dr. Amy Millen writes, "Most people have heard that you should eat carrots to help your vision....

If you have had your vitamin D levels tested, it’s important to understand what the results mean, and what action you might need to take. The blood test that measures vitamin D is called a 25(OH)D blood test. The results of the blood test can tell you whether you’re getting too little, too much or the right amount of vitamin D. This will help you to decide whether to take more or less...

According to the U.S. Department of Health and Human Services, vitamin D3 is essential for the "formation, growth, and repair of bones and for normal calcium absorption and immune function" and there are studies to suggest that "higher levels of vitamin D in the blood are associated with reduced risks of colorectal cancer.   It is crucial for the absorption and metabolism...