Supplementation with iron and riboflavin enhances dark adaptation response to vitamin A–fortified rice in iron-deficient, pregnant, nightblind Nepali women

Abstract

Background: Nightblindness affects 16 -52% of pregnant women in areas of Nepal and in some cases persists after vitamin A treatment. Iron and riboflavin affect vitamin A utilization and photoreceptor function, respectively, and pilot data in the study population showed a high prevalence of iron and riboflavin deficiencies. Objective: The objective was to assess the effect of supplemental iron and riboflavin on pupillary threshold (PT) and plasma retinol in nightblind, pregnant Nepali women given vitamin A-fortified rice. Design: Nightblind pregnant women were randomly assigned to receive, 6 d/wk under supervision for 6 wk, a vitamin A-fortified rice curry dish providing 850 g retinal activity equivalents/d with either a 30-mg Fe and 6-mg riboflavin (FeR ѿ VA) capsule or a placebo control (VA only) capsule. Hemoglobin, erythrocyte riboflavin, and plasma ferritin and retinol were measured before and after the intervention. Dark adaptation was assessed by PT score. Results: Women who were iron deficient at baseline (n ҃ 38) had significantly greater improvement in PT score with iron and riboflavin supplementation than without (P ҃ 0.05). Iron and riboflavin supplements significantly reduced the prevalences of riboflavin deficiency (from 60% to 6%; P 0.0001), iron deficiency anemia (from 35% to 15%; P 0.007), and abnormal PT (from 87% to 30%; P 0.05) from baseline. Mean increases in erythrocyte riboflavin (P 0.0001) and plasma ferritin (P ҃ 0.01) were greater in the FeR ѿ VA group than in the VA only group. Conclusions: Iron deficiency may limit the efficacy of vitamin A to normalize dark adaptation in pregnant Nepali women. Further studies are needed to assess the effect of simultaneous delivery of iron and vitamin A for the treatment of nightblindness.Am J Clin Nutr 2007;85: 1375-84.

B Vitamins in Breast Milk: Relative Importance of Maternal Status and Intake, and Effects on Infant Status and function

“…Reported prevalences include 77% in lactating urban Guatemalan women (LH Allen and MT Ruel, unpublished data), 85% in night-blind pregnant Nepali women (21), 14% in Ghanaian infants (4), 30% in Kenyan school children (22), and in 1982, nearly all pregnant and lactating women and their infants in The Gambia (23). Recently, it was reported that 66% of adults in the UK, if they are low milkconsumers, have marginal riboflavin status correctable by supplementation (24).…”

Common Metabolic Profile in Infants Indicating Impaired Cobalamin Status Responds to Cobalamin Supplementation

“…There are scarce reports on PLP and riboflavin in infants, but studies from both highincome and low-income countries have reported a rather high deficiency incidence of both vitamins among pregnant and lactating women (99,107,271), something which may have serious implication for their breastfed infants.…”

Current Capabilities and Limitations of Stable Isotope Techniques and Applied Mathematical Equations in Determining Whole-Body Vitamin A Status

“…Specifically, studies in pregnant women have shown greater improvements in the relative dose-response test and in dark adaptation when VA was coadministered with iron or iron plus riboflavin, compared with VA supplementation alone. 79,80 Reduced plasma retinol concentrations have been observed in anemic rats, 81 even when animals were fed a VA-rich diet, 82 and are associated with VA accumulation in the liver and a higher molar ratio of liver retinyl esters/retinol. 82,83 These relationships have also been investigated by model-based compartmental analysis, which showed decreased absorption of VA and inhibited mobilization of VA stores in diet-induced iron deficiency in rats.…”