Overview of Phosphorus-Wasting Diseases and Need for Phosphorus Supplements

Phosphorus (P) intake in Western countries exceeds the nutritional recommendations two- to three-fold, and the increased use of food additive phosphates by the food industry has augmented total P intake with an estimated 10% to 50% of the total P intake coming from additives. Moreover, in food composition databases, P contents of the recipe-based foodstuffs are calculated based on nutrient content of raw materials and not on chemically analyzed values of the finished food product. Thus, the amount of phosphate from additives may not have been taken into account when estimating the total P content. The chemical composition of a foodstuff affects the bioavailability of P. Both human (in vivo) and in vitro studies have shown that bioavailability of P differs between the foodstuffs. Bioavailability of P is higher in processed, phosphate additive–containing foods, such as in processed meats, baking powder–containing bakery products, processed cheeses, and cola drinks. In contrast, P bioavailability of plant-based products is low, especially in legumes and seeds. In cereals, P bioavailability increases during processing when, for example, the bread is fermented and P from phytate is released as absorbable, inorganic P through the action of microbial phytase. Phosphorus bioavailability from animal-based products is generally high, with the exception of cottage cheese. Thus, effects of P on health may depend on the source from which it is ingested. However, there is a growing need to develop research methods by which P bioavailability can be taken into account. Data on the use of food additive phosphates by the food industry and updated information on P content in foodstuffs are also needed.