March 16, 2007
SHANGHAI: A panel of medical and nutritional professionals has rebuked an essay published in the February 28 issue of the JAMA (Journal of the American Medical Association), which claimed that taking vitamins increases the risk of death.
Gathered at a recent symposium on vitamin C, the experts agreed that a balanced intake of vitamins and minerals is actually beneficial, not harmful, to one's well-being.
The group said that the study by Serbian doctor Goran Bjelakovicon was "biased and selective".
Dr Hong Zhaoyi from Shanghai's Xinhua Hospital said that many of the test subjects were suffering from serious diseases, such as cancer and vascular disease, which invalidated the findings.
He said the test would have produced very different results if it had used healthy people. In addition, he said that no systematic analysis was carried out to determine the causes of death.
Yin Shi'an, director of the Children's and Women's Nutrition Office, part of the China Disease Control Center, also expressed his concerns regarding the validity of the results: "Members of the test group were given higher than recommended doses of vitamin supplements," he said.
Doctor Balz Frei of Oregon State University in the United States said that a person's daily intake of vitamin C should not exceed 2 grams.
The study's hypotheses that vitamin intake can lead to conditions such as increased oxalate and kidney stone formation, as well as uric acid concentrations, were unfounded, Frei said.
While a daily intake of more than 2 grams might lead to symptoms like diarrhea or gastrointestinal disturbances, these are not serious, especially as vitamin C is water-resolvent and is discharged through urine, Frei said.
Source: China Daily