Iron absorption in young Indian women: the interaction of iron status with the influence of tea and ascorbic acid.
BACKGROUND
Ascorbic acid (AA) enhances and tea inhibits iron absorption. It is unclear whether iron status influences the magnitude of this effect.


OBJECTIVE
We evaluated the influence of the iron status of young women on iron absorption from a rice meal with or without added tea or AA.


METHODS
Two stable-isotope iron absorption studies were made in 2 groups of 10 subjects with iron deficiency anemia (IDA) and 10 subjects who were iron replete (control subjects). In study 1, the reference rice meal was fed alone or with 1 or 2 cups of black tea. In study 2, the reference meal was fed alone or with AA (molar ratio to iron, 2:1 or 4:1). Iron absorption was measured by the erythrocyte incorporation of (57)Fe and (58)Fe labels at 14 d.


RESULTS
Mean fractional iron absorption from the reference rice meal was approximately 2.5 times as great in the IDA group as in the control group (P < 0.05). The consumption of 1 or 2 cups of tea decreased iron absorption in the control subjects by 49% (P < 0.05) or 66% (P < 0.01), respectively, and in the IDA group by 59% or 67% (P < 0.001 for both), respectively. AA (molar ratio to iron, 2:1 or 4:1) increased iron absorption by 270% or 343%, respectively, in control subjects and by 291% or 350%, respectively, in subjects with IDA (P < 0.001).


CONCLUSIONS
The inhibitory effect of tea and the enhancing effect of AA on iron absorption were similar in the 2 groups. Overall differences in iron absorption in the 2 groups, however, continued to be dictated by iron status.
Thankachan
Prashanth
P
Division of Nutrition, St John's Research Institute, St John's National Academy of Health Sciences, Bangalore, India.
Walczyk
Thomas
T
Muthayya
Sumithra
S
Kurpad
Anura V
AV
Hurrell
Richard F
RF
D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000178:diet therapy / Q000378:metabolism*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001682:Biological Availability; D016022:Case-Control Studies; D018592:Cross-Over Studies; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D007503:Iron Isotopes; D019266:Iron, Dietary / Q000493:pharmacokinetics*; D009752:Nutritional Status; D013662:Tea / Q000737:chemistry*
D007503:Iron Isotopes; D019266:Iron, Dietary; D013662:Tea; D001205:Ascorbic Acid