Humans get most of their needed vitamins in the foods that they eat. Those are the body s ingested vitamins. Of those ingested vitamins, some are fat-soluble and others are water-soluble. The solubility of the vitamins reveals just how well the human body can manage to retain those same vitamins.

Vitamins A, D, E and K are fat-soluble vitamins. They are found in foods that contain fats and oils. For example Vitamin A can be obtained by eating fat-containing dairy products and liver. Limited amounts of Vitamin D are provided by consumption of dairy products and egg yolks. Vegetable oils contain Vitamin E. Fat soluble fats are absorbed in the intestine and stored in the body.

The water-soluble vitamins,

Vitamin B and Vitamin C, cannot be stored by the body. The water-soluble vitamins are absorbed directly into the blood stream. During one 24-hour period, if a person consumes more Vitamin B or more Vitamin C than he or she needs, that person has no way to store the unused vitamins. Those excess vitamins are lost in the sweat or the urine. Water-soluble vitamins must be included in the daily diet, so that used and lost vitamins can be replaced every 24 hours.

Some Vitamin K comes from ingested food, and some comes from the intestine, where it is produced by intestinal bacteria. A large portion of the body s needed Vitamin D comes from sunshine. Technically, an inactive form

of Vitamin D is manufactured in the skin upon its exposure to sunlight. That inactive vitamin is then activated in the liver and kidney.

Esther John, M.D., a researcher at the Northern California Cancer Center in Fremont, CA, has studied the metabolic events that produce Vitamin D. She has found that Calcitriol is an important metabolite of Vitamin D. Calcitriol appears able to slow the growth of prostate cancer cells.

Dr. John s findings highlight the potential value of all vitamins.

Jeanette Pollock is a freelance author and website owner of [http://www.vitamin-supplement-hq.com]vitamin-supplement-hq.com. Visit Jeanette’s site to learn more about [http://www.vitamin-supplement-hq.com/2006/07/11/types-of-vitamins/]the different types of vitamins.