🧪 Phosphorus

Phosphorus is an important mineral. Together with calcium, it builds bones and teeth: about 80–85% of the body's phosphorus is found there. It is also part of cells, DNA and the cell's “battery” — a substance called ATP that the body uses to store energy.

Milk and dairy products give a lot of phosphorus. A glass of skimmed milk (about 240 ml) has about 250 mg. A serving of Greek yogurt has about 310 mg. The phosphorus in milk is bound to the protein casein and to calcium. Phosphorus from animal foods is absorbed better than from beans, nuts and grains.

Phosphorus or phosphate? In food the two meet in different places. The phosphorus in milk is natural and bound to the protein casein and to calcium. Phosphates, by contrast, are often added to ready meals and fizzy drinks, which is one reason people tend to eat more phosphorus than they need. Phosphorus from animal foods such as dairy is absorbed better than from beans, nuts and grains. And phosphorus works with calcium: together they build bones and teeth, so milk, which has both, suits a healthy person well.

At the dairy chiller of a supermarket, skimmed milk and Greek yogurt are the clearest dairy sources: a glass of skimmed milk (about 240 ml) has roughly 250 mg of phosphorus and a serving of Greek yogurt about 310 mg. On ready meals and fizzy drinks, read the ingredients list for added phosphates. Phosphorus in milk is natural, bound to casein and calcium, so a plain pack of milk or yogurt needs no such check. People with kidney disease should ask their doctor.

Adults need about 700 mg of phosphorus a day. Shortage is rare: the kidneys can hold on to phosphorus when there is little of it. The opposite is more common — people eat more than they need. Phosphates are often added to ready meals and fizzy drinks. For people with kidney disease, too much phosphorus is dangerous: their kidneys have trouble removing it. Doctors often advise such people to limit phosphorus in their diet. For a healthy person, milk helps get the right amount of phosphorus.