provides additional support for a role of nonprotein sulfate in sulfation and metabolism of phenolic compounds (Hoffer et al., 2001). In humans, sulfate ingestion would almost always exceed 3 g/day as a result of sulfate ingestion in food and water, together with the sulfate produced in the body from metabolism.

Growth responses in chicks and rats occur when sulfate is added to low-sulfate diets that are deficient in cysteine (Byington et al., 1972; Sasse and Baker, 1974b); nitrogen retention is improved in humans placed under a similar dietary regimen (Zezulka and Calloway, 1976). Whether sulfate incorporation into 3′-phosphoadenosine-5′-phosphosulfate (PAPS), or whether PAPS synthase activity could be used as a measure of sulfate adequacy, is not known. The one human study conducted to date did not attempt to measure these parameters (Zezulka and Calloway, 1976). Because sulfate is an obligatory end product of sulfur amino acid turnover, inadequate sulfate consumption (or production) is unlikely to occur in any setting other than where protein deficiency is also present.

Limited information is available on the extent to which 3′-phosphoadenosine-5′-phosphosulfate (PAPS) biosynthesis can be affected by available inorganic sulfate. Whether increased amounts of PAPS are needed in diseases, such as arthritis, in which sulfated compounds (e.g., sulfates of glucosamine and chondroitin) are implicated is unknown because in most studies sufficient sulfur amino acids are provided as part of dietary protein (Hoffer et al., 2001). The primary factor affecting a dietary need for sulfate is the extent to which sulfur-containing compounds are available for degradation to provide sulfate for PAPS biosynthesis. Unlike most other nutrients, the body’s need for sulfate can be met by consuming other required nutrients, sulfur amino acids. Thus a deficiency of sulfate is not found in humans consuming normal protein intakes with adequate sulfur amino acids. Ingestion of methionine, cysteine, and glutathione in foods, along with consumption of other sulfated compounds in both food and beverages, is sufficient to meet the body’s requirement for sulfate.

Sulfate requirements for the growing fetus are high (Cole and