ATLANTA, GEORGIA. Several studies have found that diabetics have lower blood levels of vitamin C than do healthy people. Researchers at the Centers for Disease Control and Prevention recently compared 237 patients with newly diagnosed diabetes with 1803 persons without diabetes and concluded that vitamin C levels were indeed lower in the diabetics. This held true even when adjusting for age and sex. However, once adjustments for total vitamin C intake, smoking, alcohol consumption, education, body mass index, race, and physical activity level were included there were no significant differences in vitamin-C levels among the two groups. The researchers conclude that it is necessary to account for all factors affecting serum vitamin C concentrations when comparing levels in diabetics and non-diabetics. An even more intriguing finding derived from the study is the fact that the healthy group of people tended to have a significantly larger average intake of vitamin C supplements (265 mg/day) than did the diabetics (160 mg/day). The vitamin C contribution from food was similar in both groups at 104 mg/day.
Will, Julie C., et al. Serum vitamin C concentrations and diabetes: findings from the third National Health and Nutrition Examination Survey, 1988-1994. American Journal of Clinical Nutrition, Vol. 70, 1999, pp. 49-52