Phosphorus

Almost all of the food groups contain phosphorus. The best sources are foods that are high in protein. These include milk, meat, poultry, fish, and eggs. Legumes and nuts are also good sources. Fortified milk, which has Vitamin D added to it, helps the body absorb phosphorus and calcium.

Diets that have enough protein and calcium will usually have enough phosphorus. Phosphorus is common enough in plant foods that vegetarians who eat a varied diet will get enough of the mineral.

Following are some common foods and the amount of phosphorus found in them:

• milk (1 cup) - 230 milligrams (mg)
• lean ground beef (3 ounces) - 60 mg
• tofu (1 cup) - 120 mg
• peanut butter (2 tablespoons) - 105 mg
• cheddar cheese (1 ounce) - 145 mg
• cooked kidney beans (1/2 cup) - 125 mg

Phosphorus has many important functions in the body. It combines with calcium to form strong teeth and bones. It is part of the genetic material present in every cell. Phosphorus plays key roles in the metabolism of carbohydrates, proteins, and fats that come from the diet. It helps to move fat through the bloodstream. It also helps activate the B vitamins and is vital to the growth, maintenance, and repair of all body tissue. Phosphorus is important in muscle contraction (including the heart), kidney function, and nerve transmission. The functions of phosphorus are closely related to those of calcium and magnesium.

The recommended amount of phosphorus a person should get each day is similar to that of calcium. The recommended daily allowance, or RDA, for adults is 800 mg. Pregnant or breastfeeding women should get 1200 mg daily.

It is quite easy to get enough phosphorus because it is found in so many foods. Deficiencies are rare. A person who takes an antacid with aluminum hydroxide for a long time could have symptoms of a deficiency, including:

• osteoporosis, or bone thinning
• weakness
• loss of appetite
• muscle pain

Getting too much phosphorus, from drinking too many carbonated drinks or eating too much meat, can cause adverse affects. High phosphorus levels can interfere with calcium absorption. This can eventually lead to poor bone maintenance and osteoporosis, or brittle bones. Excess phosphorus can also interfere with the absorption of iron.