U.K. Targets Vitamin, Mineral Supplements in Intake Recommendations

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

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

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

Of particular concern to EVM and FSA was chromium picolinate, which FSA said has the potential to cause cancer and should be banned from use in food supplements. EVM issued guidance on chromium, saying intakes of .15 mg/kg/d would not be expected to cause adverse events--although this guidance specifically excluded hexavalent forms of chromium, as well as chromium picolinate.

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

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

James Komorowski, director of technical affairs at Purchase, N.Y.-based Nutrition 21, added, "The information that we have on the safety of chromium picolinate shows that it is safe and there is no link to cancer--there have been no cases of cancer and no suggestion of cancer. ... We have an abundance of carcinogenicity studies showing that [Chromax® chromium picolinate is] 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 cause abdominal pain and diarrhea, with similar symptoms occurring with calcium intakes 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 noted that women of childbearing age should be taking a dietary supplement of .4 mg/d of folic acid, as well as consuming a diet high in the nutrient to reduce the risk of neural tube defects. FSA also indicated women may need iron supplementation to combat high blood losses during menstruation, and vitamin D is necessary during lactation. FSA also stated that children from the age of six months to two years "benefit from vitamin drops," including vitamins A, C and D.

"[FSA's] position on vitamin C, zinc and beta-carotene is simply what I would call precaution run amuck," Hathcock said. "We all agree that especially zinc has the potential to have adverse effects when taken in really huge quantities. That's not the debate. The debate is what the numerical limit be."

Numerical limits in the form of safe upper levels were set for eight nutrients: 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 to set upper limits, EVM issued guidance for intake.

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