Abstract

This study investigated the effects of vitamin C supplementation on the nutritional iron status of 31 adolescent girls, aged 12-15 years, with low hemoglobin levels. They were randomly divided into four groups, and for two groups daily150 mg or 900 mg of L-ascorbic acid(AsA) was given in three equal doses at three meals during 9 weeks. To another group daily 60 mg iron as ferrous sulfate was given in the same way as AsA. The control group was given sugar placebo. Body iron status was monitored through the determination of Hb, Hct, MCHC, and serum ferritin concentrations. Dietary AsA and iron intakes were measured from food consumption surveys performed by 3-day 24-hour recalls. The amount of absorbed iron was estimated from the model of Monsen et al. The average amounts of food iron for four groups were 12.3- 15.0 mg and 11.1 - 18.9 mg at initial and at final period of the supplementation trial, respectively. The tentatively estimated amount of absorbed iron was significantly increased in the 900 mg AsA and iron supplementing groups, but not in the 150 mg AsA and placebo groups. Both Hb and MCHC were improved to above normal levels in all groups except the placebo group. Hct was elevated only in the AsA 900 mg group whose Hct was relatively lower than the other groups. Serum ferritin concentrations of the four groups, which were as low as 8.50 - 14.39ng/mL on average at the intial periods, augmented significantly to 20.18ng/mL and 26.63ng/mL in the 900 mg AsA and iron groups, respectively. Serum ferritin was not elevated in either the AsA 300 mg group or the placebo group. The above data indicated that the daily supplementaion of 150 mg AsA to the meals containing 12-15 mg iron per day promoted Hb levels of adolescent girls with low Hb, and the 900 mg AsA supplementing improved not only Hb level but also body iron store. A supplementation of 60 mg iron per day appeared to be slightly more effective in improving the iron status in comparison to the 900 mg AsA supplement.

• Keywords: vitamin C supplementaion; adolescent girls; hemoglobin; MCHC; serum ferritin