Vitamin D deficiency is one of the most common nutrient deficiencies. This is important, because vitamin D is absolutely essential for optimal health. Unfortunately, only a handful of foods contain significant amounts of this vitamin.
12 Common Diseases Caused by Vitamin D Deficiency(**im extremely deficient and with a form of lupus I'm "not" suppose to be in the sun nor like the D foods well the popular foods. So I'm on d supplant and a close watch-Amber)
Vitamin D Supplement Warning!
Why I don't take vitamin D supplements | Butter Nutrition