Chromium deficiency is a proposed disorder that results from an insufficient dietary intake of chromium. Chromium was first proposed as an essential element for normal glucose metabolism in 1959, and was widely accepted as being such by the 1990s. Cases of deficiency have been claimed in hospital patients who were fed defined liquid diets intravenously for long periods of time. By the turn of the century, these views were being challenged, with subsequent work suggesting that chromium supplements may present a health risk. In spite of this, dietary supplements containing chromium remain widely available.
Video Chromium deficiency
Signs and symptoms
The symptoms of chromium deficiency caused by long-term total parenteral nutrition are severely impaired glucose tolerance, weight loss, and confusion. However, subsequent studies questioned the validity of these findings.
Maps Chromium deficiency
Supplementation
The European Food Safety Authority concluded that chromium is not an essential nutrient, making this the only mineral for which the United States and the European Union disagree. The proposed mechanism for cellular uptake of CrIII via transferrin has been called into question. There is no proof that chromium supplementation has physiological effects on body mass or composition, and its use as a supplement may be unsafe. A 2014 systematic review concluded that chromium supplementation had no effect on glycemic control, fasting plasma glucose levels, or body weight in people with or without diabetes.
Chromium may be needed as an ingredient in total parenteral nutrition (TPN), since deficiency may occur after months of intravenous feeding with chromium-free TPN. For this reason, chromium is added to normal TPN solutions for people with diabetes, and in nutritional products for preterm infants.
Diagnosis
Dietary recommendations
The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for chromium in 2001. For chromium there was not sufficient information to set EARs and RDAs, so needs are described as estimates for Adequate Intakes (AIs). The current AIs for chromium for women ages 14 and up is 25 ?g/day up to age 50 and 20 ?g/day for older. AI for pregnancy is 30 ?g/day. AI for lactation is 45 ?g/day. For men ages 14 and up 35 ?g/day up to age 50 and 30 ?g/day for older. For infants to children ages 1-13 years the AI increases with age from 0.2 to 25 ?g/day. As for safety, the IOM sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of chromium there is not yet enough information and hence no UL. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs).
The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States. The EFSA does not consider chromium to be an essential nutrient, and so has not set PRIs, AIs or ULs. Chromium is the only mineral for which the United States and the European Union disagree on essentiality.
For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For chromium labeling purposes 100% of the Daily Value was 120 ?g, but as of May 27, 2016 it was revised to 35 ?g to bring it into agreement with the RDA. A table of the old and new adult Daily Values is provided at Reference Daily Intake. Food and supplement companies have until July 28, 2018 to comply with the change.
It is thought that few Americans are chromium deficient.
Approximately 2% of ingested chromium(III) is absorbed, with the remainder being excreted in the feces. Amino acids, vitamin C and niacin may enhance the uptake of chromium from the intestinal tract. After absorption, this metal accumulates in the liver, bone, and spleen. Trivalent chromium is found in a wide range of foods, including whole-grain products, processed meats, high-bran breakfast cereals, coffee, nuts, green beans, broccoli, spices, and some brands of wine and beer. Most fruits and vegetables and dairy products contain only low amounts. Most of the chromium in people's diets comes from processing or storing food in pans and cans made of stainless steel, which can contain up to 18% chromium. The amount of chromium in the body can be decreased as a result of a diet high in simple sugars, which increases the excretion of the metal through urine. Because of the high excretion rates and the very low absorption rates of most forms of chromium, acute toxicity is uncommon.
See also
- Chromium toxicity
References
Further reading
- "Dietary Supplement Fact Sheet: Chromium". Office of Dietary Supplements, National Institutes of Health. Retrieved 24 February 2013.
- Chromium in glucose metabolism
Source of article : Wikipedia
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