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 B12 deficiency anemia its first step, of taking an oral dose of radiolabelled vitamin B, followed by quantitation of the vitamin in the patient's urine over a 24-hour period via measurement of the radioactivity. A second step of the test repeats the regimen and procedure of the first step, with the addition of oral intrinsic factor. A patient with PA presents lower than normal amounts of intrinsic factor; hence, addition of intrinsic factor in the second step results in an increase in vitamin B absorption (over the baseline established in the first). The Schilling test distinguished PA from other forms of B deficiency,