Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005) / Chapter Skim
Currently Skimming:
7 Sulfate
7 Sulfate
Pages 424-448
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 424... ...
While significant levels of sulfate are found in foods and various sources of drinking water, the major source of inorganic sulfate for humans is from biodegradation due to body protein turnover of the sulfur amino acids methionine and cysteine. Dietary sulfate in food and water, together with sulfate derived from methionine and cysteine found in dietary protein and the cysteine component of glutathione, provides sulfate for use in PAPS biosynthesis.
|
From page 425... ...
estimated that global SO2 emissions have more than doubled over the last 50 years. Sulfate improves growth in farm animals consuming diets deficient in sulfur amino acids and very low in sulfate.
|
From page 426... ...
There are hundreds of sulfur-containing compounds in the human body, and the body synthesizes all of them, with the exception of the vitamins thiamin and biotin. Precursors include sulfate obtained from dietary intake and ingestion of the indispensable amino acids methionine and cysteine (cysteine is considered conditionally indispensable)
|
From page 427... ...
. Clinical Effects of Inadequate Intake Extensive work with laboratory animals has shown that growth is stunted when dietary sulfate is purposely eliminated from both the food and water supply and when sulfur amino acids, particularly cysteine, are provided at levels resulting in deficiency signs.
|
From page 428... ...
Using similar dietary conditions in adult men (low sulfate, sulfur amino acid-deficient diet) , nitrogen retention increased when sodium sulfate was added to the diet in an amount equivalent to that provided by additional methionine (Zezulka and Calloway, 1976)
|
From page 429... ...
are implicated is unknown because in most studies sufficient sulfur amino acids are provided as part of dietary protein (Hoffer et al., 2001)
|
From page 430... ...
Recommended intakes have already been established for sulfur amino acids, which would thus cover the need for inorganic sulfate (IOM, 2002/2005)
|
From page 431... ...
. Thus the methodology was designed to mimic the digestive process in TABLE 7-2 Sulfate Content of Selected Foods Number Mean Sulfate Content, mg/g Food of Samples (standard deviation)
|
From page 432... ...
Moreover, sulfite, as well as other inorganic sulfur compounds in the +4 valence state (e.g., SO2, HSO31–) are highly bioactive and have well-known toxic side effects (Til and Feron, 1992; Wedzicha, 1992)
|
From page 433... ...
The Third National Health and Nutrition Examination Survey has not estimated sulfate intake directly. Indirect estimates of sulfate intake can be calculated from the intakes of sulfurcontaining amino acids.
|
From page 434... ...
29,015 1.95 0.76 1.01 a M = male, F = female, P/L = pregnant and/or lactating. NOTE: Sulfate content calculated using 0.7 g sulfate/g of sulfur amino acid from the Third National Health and Nutrition Examination Survey (1988–1994)
|
From page 435... ...
of 0 and 1,200 mg/L for two consecutive 6-day periods. In the dose-ranging study, the mean sulfate intake coming from drinking water in the 1,200 mg/L group was 2.7 g, while the mean sulfate intake in drinking water in the single-dose study at 1,200 mg/L was 2.9 g due to differences in total water consumed.
|
From page 436... ...
The comparatively poor absorption of magnesium thus may be the primary ion responsible for the diarrhea seen since absorption of sulfate was much greater. TABLE 7-5 Case Reports of Infants Exposed to High Levels of Sulfate Sulfate in Median Water Sulfate Sulfate Weighta Intakeb Water Supply Dose Dose Subject (mg/L)
|
From page 437... ...
The median sulfate concentration of water samples and the mean daily sulfate intake for infants who did not develop diarrhea were 258 mg/L and 29 mg/kg/day, respectively. For infants who developed diarrhea, the median water sulfate concentration was 289 mg/L, and the mean daily sulfate intake was 28 mg/kg/day.
|
From page 438... ...
. While neither growth rate nor voluntary dietary intake during the 18-day study was affected by sulfate dose, nonpathogenic diarrhea became evident at sulfate concentrations greater than 1,200 mg/L (based on an estimated water intake of ≈1,440 mg/kg/day)
|
From page 439... ...
. It is now clear that sulfate can also enter the colon from unabsorbed dietary sulfate as well as from unabsorbed sulfur amino acids, taurine, and sulfurcontaining food additives (e.g., sulfur dioxide, sulfites, and carrageenan)
|
From page 440... ...
Dose-Response Assessment Adults Adverse effects that have been associated with sulfate ingestion include osmotic diarrhea and ulcerative colitis. Generally, a selfregulating effect occurs in that higher concentrations of water sulfate have an odor and off taste, which causes those exposed to water with a high sulfate content to use bottled water.
|
From page 441... ...
Mean daily sulfate intake for infants who did not develop diarrhea was 29 mg/kg/day, while the mean daily sulfate intake of infants developing diarrhea was 28 mg/kg/day. In a small-case series, infants exposed to water sulfate concentrations above 600 mg/ L (estimated intake about 66 mg/kg)
|
From page 442... ...
Hyperthyroidism increases basal metabolic rate which, in turn, increases protein catabolism. Increased serum sulfate levels have been noted in hyperthyroidism, probably due to increased breakdown of protein and thus sulfur amino acids (Tallgren, 1980)
|
From page 443... ...
ingestion predisposes individuals to ulcerative colitis, and the role of hydrogen sulfide in its etiology. • Studies to determine how much of the sulfate produced via turnover in metabolism reenters the bowel and thus may serve as an irritant or oxidant.
|
From page 444... ...
2000. The clinical chemistry of inorganic sulfate.
|
From page 445... ...
1992. The splanchnic organs, liver and kidney have unique roles in the metabolism of sulfur amino acids and their metabolites in rats.
|
From page 446... ...
1983. Serum concentration and renal excretion by normal adults of inorganic sulfate after acetaminophen, ascorbic acid, or sodium sul fate.
|
From page 447... ...
1973. An optimal level of inorganic sulfate for the diet of a rat.
|
From page 448... ...
1980. Inorganic sulfates in relation to serum thyroxin level and in renal failure.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.