U.K. Targets Vitamin, Mineral Supplements in IntakeRecommendations

U.K. Targets Vitamin, Mineral Supplements in IntakeRecommendations

LONDON--England's Food Standards Agency (FSA) released newadvice May 8 on healthy intakes of vitamins and minerals, noting that some canhave harmful effects when taken in high doses. The advice was given with regardto Safe Levels for Vitamins and Minerals, a 360-page report issued by theExpert Group on Vitamins and Minerals (EVM) that covered 31 nutrients. Thereport is broken into sections on water- and fat-soluble vitamins, traceelements, and minerals.

"It has been argued that since vitamins and minerals are essential forhuman health, it is not appropriate to assess them in the same way in whichother chemicals added to food are assessed," EVM wrote in its report."However, since there is much evidence that excessive intakes of somevitamins and minerals can cause harm, it is not appropriate to exclude essentialnutrients from the safety assessment that is applied to other chemicalsubstances which are added to foods."

EVM indicated that high intakes of some nutrients over long periods of timehave been linked with adverse events. Namely, nicotinic acid has been linkedwith liver dysfunction, vitamin B6 with neuropathy, boron and manganese withreproductive toxicity, and vitamin A with permanent damage to the liver, boneand vision, as well as chronic muscular and skeletal pain in some cases. EVMalso pointed out beta-carotene can cause a reversible yellowing of the skin thatgoes away when supplementation is stopped; however, the report also indicatedthe nutrient may increase the risk of lung cancer in smokers.

Of particular concern to EVM and FSA was chromium picolinate, which FSA saidhas the potential to cause cancer and should be banned from use in foodsupplements. EVM issued guidance on chromium, saying intakes of .15 mg/kg/dwould not be expected to cause adverse events--although this guidancespecifically excluded hexavalent forms of chromium, as well as chromiumpicolinate.

"Unlike other forms of trivalent chromium, chromium picolinate was shownto cause DNA damage in mammalian cells in vitro," the authors wrote."Additionally, two case reports have associated renal failure with the useof chromium picolinate supplements."

John Hathcock, Ph.D., vice president of nutritional and regulatory science atthe Council for Responsible Nutrition commented to FSA last year when EVM'sreport was under review. "My comment was that they had done a 'curious'scientific evaluation that led to the conclusion [that chromium picolinateshould be banned], and I pointed out that I thought it was erroneous," hesaid. Hathcock added that the expert group based its guidance for safe intakesof chromium on animal studies conducted with chromium picolinate. "When youdo a chromium picolinate test in an animal, you're bringing chromium andpicolinic acid in together, yet they concluded that the chromium part of it wasvalid but the picolinic acid part was not. To me that makes no scientific senseat all."

James Komorowski, director of technical affairs at Purchase, N.Y.-basedNutrition 21, added, "The information that we have on the safety ofchromium picolinate shows that it is safe and there is no link to cancer--therehave been no cases of cancer and no suggestion of cancer. ... We have anabundance of carcinogenicity studies showing that [Chromax chromium picolinateis] safe, as well as animal and human data also concluding that it's safe."

FSA also picked on vitamin C, saying intakes above 1,000 mg/d can causeabdominal pain and diarrhea, with similar symptoms occurring with calciumintakes above 1,500 mg/d and iron intakes above 17 mg/d. FSA did note, however,that these effects are reversible when supplementation is stopped.

Contrary to the harsh treatment of several nutrients, FSA specifically notedthat women of childbearing age should be taking a dietary supplement of .4 mg/dof folic acid, as well as consuming a diet high in the nutrient to reduce therisk of neural tube defects. FSA also indicated women may need ironsupplementation to combat high blood losses during menstruation, and vitamin Dis necessary during lactation. FSA also stated that children from the age of sixmonths to two years "benefit from vitamin drops," including vitaminsA, C and D.

"[FSA's] position on vitamin C, zinc and beta-carotene is simply what Iwould call precaution run amuck," Hathcock said. "We all agree thatespecially zinc has the potential to have adverse effects when taken in reallyhuge quantities. That's not the debate. The debate is what the numerical limitbe."

Numerical limits in the form of safe upper levels were set for eightnutrients: vitamin B6 (.17 mg/kg/d), beta-carotene (7 mg/d), vitamin E (800 IU/d),boron (.16 mg/kg/d), copper (.16 mg/kg/d), selenium (.45 mg/d), zinc (25 mg/d)and silicon (25 mg/kg/d). In the events where insufficient evidence existed toset upper limits, EVM issued guidance for intake.

EVM is an independent group composed of 11 members from the medical andscientific community, one layperson, and four observers representing consumerorganizations, the health and food industries and alternative medicineinterests. The full EVM report, including nutritional and toxicological reviewsof 31 vitamins and minerals, can be viewed online (www.foodstandards.gov.uk/multimedia/pdfs/vitmin2003.pdf).