Vitamin C C deficiency. Beyond that, a role for vitamin C as prevention or treatment for various diseases is disputed, with reviews reporting conflicting results. A 2012 Cochrane review reported no effect of vitamin C supplementation on overall mortality. It is on the World Health Organization's List of Essential Medicines as one of the most effective and safe medicines needed in a health system. The disease scurvy is caused by vitamin C deficiency and can be prevented and treated with vitamin C-containing foods or dietary supplements. It takes at least a month of little to no vitamin C before symptoms occur. Early
Vitamin E deficiency from simple lack of vitamin E in a person's diet, but it can arise from physiological abnormalities. It occurs in the people in the following situations: The U.S. Institute of Medicine defines deficiency as a serum concentration of less than 12 µmol/L. Treatment is oral vitamin E supplementation. Vitamin E deficiency Vitamin E deficiency in humans is a very rare condition, occurring as a consequence of abnormalities in dietary fat absorption or metabolism rather than from a diet low in vitamin E. Collectively the EARs, RDAs, AIs and ULs for vitamin E and other essential nutrients are referred to as