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Dairy products are an important component of many human diets, and contain high levels of calcium, phosphate, and milk proteins including casein, whey, and bioactive peptides (all potential inhibitors of iron absorption). Results have been conflicting with regard to the effects of dairy products on nonheme iron absorption. Calcium supplementation has been shown to decrease both nonheme and heme iron absorption. The effect of calcium supplementation on iron absorption appears to be dose related up to approximately 300 mg calcium. Consuming dairy products 2 h either side of main meals does not appear to affect nonheme iron absorption in those meals. When considering the effects of calcium on iron absorption the relative doses and sources of calcium and iron should be considered. The inhibitory effect of calcium on iron absorption from complete diets appears to be less than that from single meals. Longer-term calcium intake over several weeks does not appear to impact on an individuals' iron status in healthy people consuming a varied diet.

Nearly one-quarter of the world's population is affected by anemia. The primary cause of anemia is iron deficiency, affecting populations in developed and developing countries. Two types of iron are found in the diet. Heme iron (in meat products) is well absorbed compared with nonheme iron (in meat and plant foods). Vitamin C and a factor in meat enhance nonheme iron absorption, while phytates, polyphenols, and some proteins inhibit it. Calcium inhibits heme and nonheme iron absorption. A range of measures should be used to prevent iron deficiency including dietary strategies that increase dietary diversity and iron intake and bioavailability, iron fortification of foods, and iron supplementation.

Dietary minerals are essential nutrients that drive key cellular and physiological functions. Each mineral is absorbed in the gut via unique, complex pathways that can involve a cascade of receptors and binding proteins. Foods can both provide dietary minerals and contain components that impact the bioavailability of minerals in the digestive system. Kiwifruit exceeds most other fruits in its content of key micronutrients including potassium, phosphorus, magnesium, calcium, iron, and folate. It also contains exceedingly high levels of ascorbic acid, which increases the bioavailability of nonheme iron and can impact on calcium absorption. Recent research in cells, animals, and humans has demonstrated that kiwifruit, particularly the gold variety, can increase the uptake and retention of the essential dietary minerals iron, calcium, phosphorus, and magnesium.