Vitamin C megadosage in combination with other therapies, but this does not imply vitamin C megadoses in themselves have therapeutic effect. The World Health Organization recommends a daily intake of 45 mg/day of vitamin C for healthy adults, and 25–30 mg/day in infants. The Vitamin C article provides examples of recommendations from individual countries. None exceed 110 mg/day. Vitamin C is necessary for production of collagen and other biomolecules, and for the prevention of scurvy. Vitamin C is an antioxidant, which has led to its endorsement by some researchers as a complementary therapy for improving quality of life. Since the 1930s, when it
Vitamin D and neurology vitamin D blood concentration standard for diagnosing hypovitaminosis D does not exist. In the past, hypovitaminosis D has been defined by blood concentrations lower than 20 ng/ mL. However, in more recent literature many researchers have considered 30 ng/ mL to be an insufficient concentration of vitamin D. Subnormal levels of vitamin D are usually caused by poor nutrition or a lack of sun exposure. Risk factors for hypovitaminosis D include premature birth, darker skin pigmentation, obesity, malabsorption, and older age. The brain requires the use of many neurosteroids to develop and function properly. These molecules are often identified as