SULFUR – THE FORGOTTEN NUTRIENT

Sulfur is an inorganic element and forms part of several molecules in the body, including amino acids, proteins, enzymes, vitamins, and more.¹ Following calcium and phosphorus, sulfur is the third most abundant mineral in the human body, representing ~0.3% of total body mass.² Dietary sulfur comes from protein where 2 of the 20 amino acids, methionine, and cysteine, contain sulfur (the sulfur-containing amino acids; SAAs). The amount of SAAs in protein varies according to the source, e.g., dairy is 4% SAAs and egg whites 8% SAAs.³ Additionally, glutathione (a natural intracellular antioxidant) provides a source of dietary sulfur and is found in fruits and vegetables.⁴ Currently, there is no recommended dietary allowance (RDA) for sulfur. There is, however, a recommended daily intake for the sulfur-containing amino acids. The estimated requirement for methionine (combined with cysteine) was determined in 1989 to be 14 mg/day per kg body weight in adults.