Vitamin C the scorbutic diet was fed. Men in both studies on a diet devoid, or nearly devoid, of vitamin C had blood levels of vitamin C too low to be accurately measured when they developed signs of scurvy and, in the Iowa study, at this time were estimated (by labeled vitamin C dilution) to have a body pool of less than 300 mg, with daily turnover of only 2.5 mg/day, implying an instantaneous half-life of 83 days by this time (elimination constant of 4 months). Vitamin C has a definitive role in treating scurvy, which is a disease caused by vitamin
Vitamin D deficiency further increasing the risk of fall and bone fractures in adults. Ultraviolet B rays from sunlight is a large source of vitamin D. Fatty fish such as salmon, herring, and mackerel are also sources of vitamin D. Milk is often fortified with vitamin D and sometimes bread, juices, and other dairy products are fortified with vitamin D as well. Many multivitamins now contain vitamin D in different amounts. Vitamin D deficiency is typically diagnosed by measuring the concentration of the 25-hydroxyvitamin D in the blood, which is the most accurate measure of stores of vitamin D in the body. Vitamin