Consuming foods rich in iron does not significantly increase the chances of pregnancy in women, a study has found.
The research, published in The Journal of Nutrition, finds that heme iron, which mostly comes from meat, has no effect on how long it takes a woman to conceive.
Researchers from Boston University in US also found that non-heme iron, which is found mainly in vegetables and dietary supplements, has a modest effect only for women who are more likely to be iron-deficient because of heavy menses or having previously given birth.
"For the average pregnancy planner, it is probably wise to take a preconception multivitamin, but more for the folic acid than for the iron content," said Elizabeth Hatch, professor at Boston University.
"If you have extremely heavy menstrual cycles, it might be a good idea to have your iron status checked by your healthcare provider," she said.
The team analysed data from over 4,600 women, who completed questionnaires every eight weeks for one year or until they conceived.
The researchers estimated heme and non-heme iron intake from the questionnaire responses about diet and about dietary supplement use.
They found no association between a woman's intake of heme iron and the number of cycles it took for her to conceive.
However, consuming more non-heme iron—both from dietary supplements and from food—was associated with a slightly increased chance of pregnancy in women who had previously given birth.