COLLOIDAL MINERALS
Arsenic

Deficiencies: The most impressive reported sign of arsenic deficiency is death of goats during lactation because of disorders in heart muscle and, to a lesser extent, skeletal muscle. The most consistent signs of arsenic deprivation in rodents have been effects on methionine metabolism. Arsenic may be important under certain circumstances in humans. For example, arsenic, independent of omega-3 fatty acids, increases bleeding time. This imps that it may be a plausible candidate for the unknown factor in fish responsible for increased bleeding time. In addition, a recent human study suggested that arsenic homeostasis is altered by hemodialysis, and that low serum arsenic is correlated with central nervous system disorders, vascular disease, and cancer.

Diet recommendations: It is inappropriate at present to give dietary recommendations for arsenic for humans because of questions of its essentiality. Based on animal studies, however, amounts of arsenic in the diet that lead to signs of arsenic deficiency can be extrapolated to humans. The suggested arsenic requirement for animals is between 25 and 50 ng As/g (based on diets containing 4000 kcal/kg). Extrapolated to the human population, this dietary intake is equal to 12.5 to 25 µg As/day. Human diets normally contain 12 to 50 µg As/day. Thus, the postulated arsenic requirement for humans apparently can be met by typical diets. However, there may be dietary situations where the requirement for arsenic is not met (for example, low dietary arsenic coupled with an altered methionine metabolism or hemodialysis).

Food sources: Arsenic (inorganic and organic) in the diet is contributed by various foods including cereals and breads, 18.1%; starchy vegetables, 14.9%; and meats and fish, 32.1%. About 20% of the daily intake of arsenic is inorganic. Arsenic in water is almost all inorganic and most drinking water contains less than 10 µg As/L and, typically, 2 to 3 µg/L. Drinking water can contribute 20 µg inorganic As/day.

Toxicity: Toxicity of organic arsenicals, including compounds such as monomethylarsonic acid, dimethylarsenic acid, arsenobetaine, and arsenocholine, is low. Inorganic forms are more toxic than organic forms of arsenic; generally arsenite (+3) is more toxic than arsenate (+5). Signs of inorganic arsenic toxicity include dermatosis, hematopoietic depression, liver damage, sensory disturbances, peripheral neuritis, anorexia, and skin and internal cancers.

For further information:

Uthus, E.O. (1994) Arsenic essentiality and factors affecting its importance. In: Arsenic Exposure and Health (Chappell, W.R., Abernathy, C.O. & Cothern, C.R., eds.), pp. 199-208. Science and Technology Letters, Northwood, UK

Anke, M. (1986) Arsenic. In: Trace Elements in Human and Animal Nutrition (Mertz, W., ed.), pp. 347-372. Academic Press, Orlando, FL.

RELATED ARTICLES

REQUEST YOUR FREE EAGLE PRODUCT INFORMATION PACK: INFOPACK@eagle-min.com