Recovery from impaired dark adaptation in nightblind pregnant Nepali women who receive small daily doses of vitamin A as amaranth leaves, carrots, goat liver, vitamin A-fortified rice, or retinyl palmitate
Haskell MJ, Pandey P, Graham JM, Peerson JM, Shrestha RK, Brown KH
Published in Am J Clin Nutr, Vol. 81 (2), pp. 461-71
Methodology
Randomised trial in night-blind pregnant women in Nepal. Six groups received vitamin A 6 days a week for 6 weeks: 850 mcg retinol equivalents a day as retinyl palmitate, fortified rice, goat liver, amaranth leaves or carrots, or 2000 mcg a day as retinyl palmitate. Dark adaptation was measured weekly by pupillary threshold.
Key Findings
Dark adaptation in the night-blind women improved from -0.71 to -1.42 log cd/m2 (P<0.0001), ending no different from women who were not night-blind (P=0.55). Plasma retinol rose from 0.95 to 1.07 micromol/L (P<0.0001), more with the higher-dose capsule and liver than with vegetables.
Conclusions
Small daily doses of vitamin A, from food or capsules, restored dark adaptation in night-blind pregnant women; liver, amaranth leaves, carrots and retinyl palmitate did not differ in effect on dark adaptation.
Limitations
No placebo group (all arms received vitamin A); the comparison is between sources. Short (6 weeks) and limited to one population. The abstract does not give group sizes.
Supplements Studied
Improvement in dark adaptation did not differ significantly
women who received vitamin A as liver, amaranth leaves, carrots, or retinyl palmitate
Related Health Concerns
Study Details
Access Study
This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.