Q. I have been looking for an explanation of safe levels of vitamin D. There is a lot of confusing information about this. I know that too little is dangerous, but what about too much?
One doctor told me that high levels of vitamin D could cause atherosclerosis. Another said that is not true and advocates levels of 90 nanograms/milliliter (ng/ml) or higher to prevent or reverse osteoporosis.
Since this bone disease runs in my family I am anxious to know where I should set my vitamin D goal.
A. No wonder you are confused. Experts are divided about optimal vitamin D levels.
People who are too low are at risk for high blood pressure, diabetes, arthritis, asthma, depression, and heart disease as well as bone loss (osteoporosis). There are also several studies linking low levels of vitamin D to a higher risk of cancer. One study found, however, that elderly Swedish men were equally likely to develop cancer if their 25-hydroxyvitamin D levels were above 40 or under 18 ng/ml (American Journal of Clinical Nutrition, Oct. 2010).
For more information about the pros and cons of this nutrient and how to improve your level safely, we are sending you our Guide to Vitamin D Deficiency.
