Phosphorus -- Backbone to Healthy Bones
Last reviewed by Faculty of Harvard Medical School on January 16, 2013
By Rebecca Lynch, M.S.,R.D.,L.D.N
Phosphorus is a mineral that works with calcium to keep bones strong and healthy. This depends on a good balance between calcium and phosphorus in your diet. Eating too much phosphorus can disrupt the balance.
The amount of calcium and phosphorus you need depends on your age, and whether you are pregnant or breastfeeding.
The recommendations below are for healthy people. People with chronic health conditions, such as kidney disease, should speak with their doctors or a dietitian regarding the amount that is right for them.
Americans, on average, tend to get too little calcium and too much phosphorus in their diets.
Some studies suggest that consuming a high-phosphorus, low-calcium diet can be harmful to bones. At most, you shouldn't consume more than three to four grams (3,000 - 4,000 milligrams) of phosphorus a day, depending on age.
Over the past 20 years, however, we have increased our phosphorus intake 10% to 15% because more phosphorus salts have been added to the food supply. They:
Phosphorus salts are more easily absorbed into the bloodstream, compared with phosphorus found naturally in food. People with kidney disease are more susceptible to a build-up of phosphorus in the blood.
A diet high in processed or convenience foods may disturb the calcium and phosphorus balance that maintains bone health. Unfortunately, food companies are not required to provide information about phosphorus content on the nutrition fact label. This makes it difficult for consumers to make good choices. To identify phosphorus salts in foods, look for "phos" in the ingredient list.
Aim for two to three servings of dairy a day. If you can't tolerate dairy, choose other foods high in calcium, or take a calcium supplement to meet your daily calcium requirement.
To avoid eating too much phosphorus, choose whole, fresh foods, when possible. Processed, convenience and fast foods can be high in phosphorus and sodium. So eat them in moderation.
Rebecca Lynch, M.S., R.D., L.D.N, completed her dietetic internship at the Brigham and Women's Hospital, Boston and received her master's degree in nutrition at the University of Vermont. She is currently a senior clinical dietitian working with people with kidney problems at Brigham and Women's Hospital.