Vitamin and C dissolve into the water when a vegetable is boiled, and are then lost when the water is discarded. The body's stores for different vitamins vary widely; vitamins A, D, and B are stored in significant amounts, mainly in the liver, and an adult's diet may be deficient in vitamins A and D for many months and B in some cases for years, before developing a deficiency condition. However, vitamin B (niacin and niacinamide) is not stored in significant amounts, so stores may last only a couple of weeks. For vitamin C, the first symptoms of scurvy in experimental
Vitamin A deficiency reference point for the extent of deficiency (with mortality increasing with severity of the eye disease). In a longitudinal study of preschool Indonesian children, susceptibility to disease increased nine times when severe VAD was present. The reason for the increased infection rate in vitamin A deficient populations is the T-killer cells require retinoids to proliferate correctly. Retinoic acid binds the promoter region of specific genes, so activates the transcription process and cell replication. A vitamin A-deficient diet will have a very limited surplus of retinol, so cell proliferation and replication will be suppressed, contributing to a reduced number of T-cells