Recovery from impaired dark adaptation does not differ among nightblind pregnant Nepali women who receive small daily doses of vitamin A as either liver, vitamin A-fortified Ultra-RiceTM, green leafy vegetables, carrots, or vitamin A capsules
Haskell, M.J.; Pandey, P.; Graham, J.M.; Peerson, J.M.; Shrestha, R.K.; Brown, K.H.
FASEB Journal 17(4-5): Abstract 680
2003
ISSN/ISBN: 0892-6638 Document Number: 254017
The purpose of this study was to assess the effect of daily supplementation with small doses of vitamin A as either preformed retinol or beta-carotene from food sources or as retinyl palmitate on dark adaptation and plasma retinol concentrations in pregnant nightblind (XN) women. XN pregnant women were randomly assigned to 1 of 6 treatment groups to receive 6 days/wk for a period of 6 weeks either 0.850 mg RE/d as: 1) retinyl palmitate, 2) vitamin A-fortified Ultra-riceTM, 3) liver 4) green leafy vegetables, 5) carrots, or 2.0 mg RE/d as 6) retinyl palmitate. Plasma retinol was measured before and after the intervention period. Dark adaptation was assessed weekly by measurement of the pupillary response threshold. These outcomes were also measured in a group of non-XN, pregnant women. The mean initial and final plasma retinol concentrations of XN women were 0.96 +- 0.05 and 1.07 +- 0.05 mumol/L (p<0.0001), respectively. The mean initial and final pupillary thresholds of XN women were -0.71 +- 0.06 log cd/m2 and -1.42 +- 0.06 log cd/m2, respectively (p<0.0001). The final mean pupillary threshold of XN women was similar to the value for the non-XN women and US women (-1.43 and -1.35 log cd/m2). Recovery from impaired dark adaptation did not differ among women who received 0.850 mg RE/d as liver, Ultra-riceTM, green leafy vegetables, carrots or as a vitamin A capsule.