Magnesium phosphates

Magnesium phosphates — including magnesium dihydrogen phosphate, magnesium hydrogen phosphate, and trimagnesium phosphate — are inorganic salts used as acidity regulators and anti-caking agents. Found in table salt, powdered foods, and bakery products, they prevent clumping and adjust pH. Trimagnesium phosphate is also used as a nutritional supplement to provide bioavailable magnesium and phosphorus.

JECFA's ADI is 70 mg per kilogram body weight per day as phosphorus, evaluated in 1982, shared with all food phosphates (E338 through E342, E450, E452). This group ADI reflects precautionary concern about cumulative phosphate intake rather than magnesium-specific toxicity. The magnesium released is nutritionally beneficial — magnesium deficiency is common in populations eating refined diets — but the phosphate component is subject to the same cumulative intake consideration as other phosphate additives.

Magnesium phosphates are approved in the EU, US (GRAS), UK, and globally. They appear in table salt, baking powder, instant dried foods, and nutritional supplements. For the general population the phosphate contribution is modest and the magnesium contribution is nutritionally positive. Individuals with chronic kidney disease should discuss total phosphate intake — from all phosphate additive sources combined — with their healthcare provider.