Fat soluble Vitamin D is one of the four vitamins that are soluble in fat (A, D, E, K), in contrast with the Bs and C who are soluble in water. Vitamins are organic molecule that the human body needs to help catalyze certain chemical reactions. Humans are unable to produce these vitamins on their own (except for Vitamin K, which is produced by bacteria in the intestine). Actually, humans can produce Vitamin D in the skin when it is exposed to sunlight, but they need to get a significant amount of sun, preferably throughout the entire year. People who live where sun is not abundant therefore do not produce enough. Glass and sunblock also block Vitamin D production in the skin. The function of Vitamin D in the body is similar to a steroid hormone. Steroids are the hormones that are fat soluble Read more [...]