Sulfur (S) is a nonmetallic element that is found mainly as part of larger compounds. 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 – occurs also as Methylsulfonylmethane (MSM). MSM has been helpful in allowing doctors to be able to lower the dosage of medication that they prescribe for pain relief. In some instances they were able to completely discontinue the medication previously prescribed. MSM supplies biologically active sulfur as a nutritional supplement.
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.
Sulfur is important to cellular respiration, as it is needed in the oxidation-reduction reactions that help the cells utilize oxygen, which aids brain function and all cell activity. These reactions are dependent on cysteine, which also helps the liver produce bile secretions and eliminate other toxins. L-cysteine is thought to generally help body detoxification mechanisms through the tripeptide compound, glutathione.
Deficiency and toxicity
There is minimal reason for concern about either toxicity or deficiency of sulfur in the body. No clearly defined symptoms exist with either state. Sulfur deficiency is more common when foods are grown in sulfur-depleted soil, with low-protein diets, or with a lack of intestinal bacteria, though none of these seems to cause any problems in regard to sulfur functions and metabolism.
There is no specific RDA for sulfur other than the amino acids of which they are part are needed to meet protein requirements. Our needs are usually easily met through diet. About 850 mg. are thought to be needed for basic turnover of sulfur in the body. There is not much information available on sulfur content of foods, nor are there supplements specifically for sulfur.
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.