b Chloride determined on molar basis equal to sodium AI or UL.
c UL = Tolerable Upper Intake Level. Based on prevention of increased blood pressure.
d ND=Not determined. Intake should be from food or formula only.
Sulfate. This nutrient is required by the body for synthesis of 3′-phosphoadenosine-5′-phosphosulfate (PAPS), which in turn is used for synthesis of many important sulfur-containing compounds such as chondroitin sulfate and cerebroside sulfate. While substantial levels of sulfate are found in foods and various sources of drinking water, the major source of inorganic sulfate for humans is from body protein turnover of the sulfur amino acids, methionine and cysteine. Dietary inorganic sulfate in food and water, together with sulfate derived from methionine and cysteine found in dietary protein, as well as the cysteine component of glutathione, provide sulfate for use in PAPS biosynthesis. Sulfate requirements are thus met when intakes include recommended levels of sulfur amino acids. For this reason, neither an Estimated Average Requirement (and thus a Recommended Dietary Allowance) nor an Adequate Intake of sulfate is established.