Back to catalogInteractions
Base foodLow concern
Milk
In plain words
The short version
A concentrated source of calcium, which competes with iron and zinc for absorption in the same meal.
Why it's green
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Safety profile
Calcium is the one mineral shown to interfere with iron absorption whatever the form of the iron, and it competes with zinc as well. Milk protein also binds some polyphenols, which is why tea with milk tastes less astringent.
The detail
Whole or skimmed dairy milk, or milk solids. Roughly 120 mg of calcium per 100 ml.
It matters for a meal built around iron — a fortified cereal, beans, greens — and hardly at all otherwise.
Sources
- Hallberg L et al. Calcium: effect of different amounts on nonheme- and heme-iron absorption in humans. Am J Clin Nutr 1991;53:112–119 (doi:10.1093/ajcn/53.1.112; PMID 1984335) — American Journal of Clinical Nutrition — abstract via US National Library of Medicine, 1991. Calcium (including from milk) reduces both non-haem and haem iron absorption
- Wood RJ, Zheng JJ. High dietary calcium intakes reduce zinc absorption and balance in humans. Am J Clin Nutr 1997;65:1803–1809 (doi:10.1093/ajcn/65.6.1803; PMID 9174476) — American Journal of Clinical Nutrition — abstract via US National Library of Medicine, 1997. Calcium (including from milk) competes with zinc absorption
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.