Nutrient Deficiency Diseases

The amounts of most nutrients, especially vitamins, needed to both prevent and treat deficiency diseases are small. The average intake of 1mg of vitamin B₁ is sufficient to prevent a deficiency disease of that vitamin, while 10mg of B₁ could cure an advanced case of someone about to die of beriberi. Although small doses of vitamins cure deficiencies, large doses of some vitamins such as A and D can be harmful since these two vitamins are already stored by the liver. Vitamins A and D are fat soluble vitamins and can accumulate to the point of becoming toxic. Most other vitamins are water soluble and are excreted in the urine throughout the day.