It is important to note that beta carotene will not help here — it must be true vitamin A best found in sufficient doses in high vitamin cod liver oil. (thehealthyhomeeconomist.com)
All molecules are toxic, in sufficient dose, even water if you drink enough in a short amount of time. (carlineconomics.com)
-- Men that are deficient in vitamin D are likely to have imbalanced (low) testosterone levels compared to those that consume sufficient doses of vitamin D. (fitnessandpower.com)