No enhancing effect of vitamin A administration on iron absorption or body total iron content in preschool children from Chengdu, China.
Study Goal
The researchers aimed to determine the effect of vitamin A supplementation on iron metabolic homeostasis in preschoolers.
Results Summary
Vitamin A supplementation increased serum retinol levels but decreased serum ferritin levels, indicating an impact on iron storage and mobilization without affecting total body iron content or intestinal iron absorption. Combined vitamin A and iron supplementation improved iron-related indices similarly to iron supplementation alone.
Population
3- to 6-year-old preschoolers
Effective Dosage
Single oral dose of vitamin A (retinol 200,000 IU)
Duration
6 months
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
vitamin A supplementation | increase | serum retinol levels | 3- to 6-y old preschoolers | - | markedly higher | #1 |
combined vitamin A and iron | increase | serum retinol levels | 3- to 6-y old preschoolers | - | markedly higher | #2 |
vitamin A supplementation | decrease | serum ferritin level | 3- to 6-y old preschoolers | - | significantly decreased | #3 |
iron supplement | increase | serum ferritin level | 3- to 6-y old preschoolers | - | increased | #4 |
iron supplement | increase | TRF-F index | 3- to 6-y old preschoolers | - | statistically increased | #5 |
iron supplement | increase | total body iron content (BTIC) | 3- to 6-y old preschoolers | - | statistically increased | #6 |
combined vitamin A and iron | increase | TRF-F index | 3- to 6-y old preschoolers | - | statistically increased | #7 |
combined vitamin A and iron | increase | total body iron content (BTIC) | 3- to 6-y old preschoolers | - | statistically increased | #8 |
vitamin A intervention | no change | total body iron content | 3- to 6-y old preschoolers | - | no direct effect | #9 |
vitamin A intervention | no change | iron absorption in the intestine | 3- to 6-y old preschoolers | - | no direct effect | #10 |
To explore the effect of vitamin A supplements on iron metabolic homeostasis for preschoolers. This was a randomized, placebo-controlled and blinded intervention trial with 3- to 6-y old preschoolers. A total of 445 subjects were randomly divided into four groups: a vitamin A supplementation group (group 1, a single oral dose of vitamin A as retinol 200,000 IU), an iron supplement group (group 2, daily oral supplement with the elemental iron 1-2 mg/kg/d for 5 d a week, lasting for 6 mo) a combined vitamin A and iron (group 3) and administration of no vitamin A or iron as a placebo-control (group 4). A total of 387 (95, 98, 90 and 104 from groups 1, 2, 3 and 4) children completed the intervention. After intervention, serum retinol levels of children in group 1 and group 3 was markedly higher than those of children in groups 2 and 4 (p<0.05). The serum ferritin level of children in group 1 significantly decreased after intervention (p<0.05), but increased in group 2 (p<0.05). The sTfR-SF index (TFR-F) and total body iron content (BTIC) showed the same change after intervention. In group 2 and group 3, the levels of TRF-F index and BTIC had statistically increased to the same degree after intervention (p<0.05). The impact of vitamin A intervention on iron metabolic homeostasis was mainly manifested in storage and mobilization; there was no direct effect on total body iron content or iron absorption in the intestine.