Sulfur represents about 0.25 percent of our total body weight, similar to potassium. The body contains approximately 140 grams of sulfur-mainly in the proteins, although it is distributed in small amounts in all cells and tissues. Sulfur has a characteristic odor that can be smelled when hair or sheep's wool is burned. Keratin, present in the skin, hair, and nails, is particularly high in the amino acid cystine, which is found in sulfur. The sulfur-sulfur bond in keratin gives it greater strength.

Sulfur is present in four amino acids: methionine, an essential amino acid; the nonessential cystine and cysteine, which can be made from methionine; and taurine, which is not part of body tissues but does help produce bile acid for digestion. Sulfur is also present in two B vitamins, thiamine and biotin; interestingly, thiamine is important to skin and biotin to hair. Sulfur is also available as various sulfates or sulfides. But overall, sulfur is most important as part of protein.

Sulfur has been used commonly since the early 1800s. Grandma's "spring tonic" consisted mainly of sulfur and molasses. This also acted as a laxative. Sulfur has been known as the "beauty mineral" because it helps the complexion and skin stay clear and youthful. The hydrogen sulfide gas in onions is what causes tearing. This gas can also be made by intestinal bacteria and is absorbed by the body or released as gas with a characteristic odor.

Sulfur is absorbed from the small intestine primarily as the four sulfur-containing amino acids or from sulfates in water or fruits and vegetables. It is thought that elemental sulfur is not used by the human organism. Sulfur is stored in all body cells, especially the skin, hair, and nails. Excess amounts are eliminated through the urine or in the feces.

Sources: As part of four amino acids, sulfur is readily available in protein foods-meats, fish, poultry, eggs, milk, and legumes are all good sources. Egg yolks are one of the better sources of sulfur. Other foods that contain this somewhat smelly mineral are onions, garlic, cabbage, brussels sprouts, and turnips. Nuts have some, as do kale, lettuce, kelp and other seaweed, and raspberries. Complete vegetarians (those who eat no eggs or milk) and people on low-protein diets may not get sufficient amounts of sulfur; the resulting sulfur deficiency is difficult to differentiate clinically from protein deficiency, which is of much greater concern.

Functions: As part of four amino acids, sulfur performs a number of functions in enzyme reactions and protein synthesis. It is necessary for formation of collagen, the protein found in connective tissue in our bodies. Sulfur is also present in keratin, which is necessary for the maintenance of the skin, hair, and nails, helping to give strength, shape, and hardness to these protein tissues. Sulfur is also present in the fur and feathers of other animals. The cystine in hair gives off the sulfur smell when it is burned. Sulfur, as cystine and methionine, is part of other important body chemicals: insulin, which helps regulate carbohydrate metabolism, and heparin, an anticoagulant. Taurine is found in bile acids, used in digestion. The sulfur-containing amino acids help form other substances as well, such as biotin, coenzyme A, lipoic acid, and glutathione. The mucopoly-saccharides may contain chondroitin sulfate, which is important to joint tissues.