This study was published in the British Journal of Nutrition 1987 May;57(3):345-53
Study title and authors:
Factors influencing the absorption of iron from soya-bean protein products.
Derman DP, Ballot D, Bothwell TH, MacFarlane BJ, Baynes RD, MacPhail AP, Gillooly M, Bothwell JE, Bezwoda WR, Mayet F.
This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/3593666?dopt=Abstract
This study compared iron absorption rates from soya-bean-based and milk-based infant formulas. The study included 138 women aged 21 to 63. None of the women were pregnant or lactating and all were unpaid volunteers. Ethical and practical considerations precluded the study being done on infants themselves.
The study found:
(a) Iron absorption was significantly less from the soya-bean formula compared to the milk-formula.
(b) The addition of ascorbic acid (vitamin C) markedly increased iron absorption from the milk-formula (a ten-fold increase), whereas ascorbic acid had a less-marked effect on the absorption of iron from the soya-bean formula, with only a two- to threefold increase.
The study reveals that iron absorption is markedly inhibited in soy infant formula.