Daily consumption of Indian spinach (Basella alba) or sweet potatoes has a positive effect on total-body vitamin A stores in Bangladeshi men.
BACKGROUND
Recent evidence suggests that the vitamin A equivalency of beta-carotene from plant sources is lower than previously estimated.


OBJECTIVE
We assessed the effect of 60 d of daily supplementation with 750 microg retinol equivalents (RE) of either cooked, puréed sweet potatoes; cooked, puréed Indian spinach (Basella alba); or synthetic sources of vitamin A or beta-carotene on total-body vitamin A stores in Bangladeshi men.


METHODS
Total-body vitamin A stores in Bangladeshi men (n = 14/group) were estimated by using the deuterated-retinol-dilution technique before and after 60 d of supplementation with either 0 microg RE/d (white vegetables) or 750 microg RE/d as sweet potatoes, Indian spinach, retinyl palmitate, or beta-carotene (RE = 1 microg retinol or 6 microg beta-carotene) in addition to a low-vitamin A diet providing approximately 200 microg RE/d. Mean changes in vitamin A stores in the vegetable and beta-carotene groups were compared with the mean change in the retinyl palmitate group to estimate the relative equivalency of these vitamin A sources.


RESULTS
Overall geometric mean (+/-SD) initial vitamin A stores were 0.108 +/- 0.067 mmol. Relative to the low-vitamin A control group, the estimated mean changes in vitamin A stores were 0.029 mmol for sweet potato (P = 0.21), 0.041 mmol for Indian spinach (P = 0.033), 0.065 mmol for retinyl palmitate (P < 0.001), and 0.062 mmol for beta-carotene (P < 0.002). Vitamin A equivalency factors (beta-carotene:retinol, wt:wt) were estimated as approximately 13:1 for sweet potato, approximately 10:1 for Indian spinach, and approximately 6:1 for synthetic beta-carotene.


CONCLUSIONS
Daily consumption of cooked, puréed green leafy vegetables or sweet potatoes has a positive effect on vitamin A stores in populations at risk of vitamin A deficiency.
Program in International Nutrition, Department of Nutrition, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA. mjhaskell@ucdavis.edu
Marjorie J
MJ
Haskell
Kazi M
KM
Jamil
Ferdaus
F
Hassan
Janet M
JM
Peerson
M Iqbal
MI
Hossain
George J
GJ
Fuchs
Kenneth H
KH
Brown
D000293:Adolescent; D000328:Adult; D000975:Antioxidants; D001459:Bangladesh; D001682:Biological Availability; D003903:Deuterium; D019587:Dietary Supplements; D006801:Humans; D007201:Indicator Dilution Techniques; D007408:Intestinal Absorption; D027723:Ipomoea batatas / Q000737:chemistry; D019684:Magnoliopsida / Q000737:chemistry; D008297:Male; D009752:Nutritional Status; D014801:Vitamin A / Q000008:administration & dosage* / Q000378:metabolism / Q000493:pharmacokinetics*; D014802:Vitamin A Deficiency / Q000097:blood / Q000517:prevention & control*; D019207:beta Carotene / Q000097:blood* / Q000378:metabolism
D000975:Antioxidants; D019207:beta Carotene; D014801:Vitamin A; D003903:Deuterium