How much phosphorus do you need per day?

The RDA for phosphorus is 700 mg a day for adults aged 19 and over.

These are the reference amounts used on US food labels and in dietary guidance, not personal targets. What you need shifts with age, pregnancy, medication and health conditions. The % Daily Value shown on every food page here is calculated against the FDA Daily Value for phosphorus, which is 1250 mg a day.

What this means for you

Seven hundred milligrams a day, and almost nothing you could do to your diet would put you below it. Phosphorus is in dairy, meat, fish, eggs, nuts, seeds, legumes and nearly every processed food, often as an additive.

A cup of sunflower seeds is more than a day's worth. Cheese, yogurt and milk supply it steadily. This is one of the few nutrients where the honest advice is that there is nothing to optimise.

Low phosphorus does happen, but it comes from medicine and illness rather than from meals. Long-term use of aluminium-hydroxide antacids binds it in the gut, severe malnutrition causes it during refeeding, and alcohol use disorder and poorly controlled diabetes contribute.

Not for everyone. If you have chronic kidney disease, this page is not written for you. Damaged kidneys cannot clear phosphorus, and the advice reverses completely. Your target comes from the team managing your kidneys.

The upper limit is 4,000 mg a day up to age 50. Reaching it from food is unusual, and very high intakes over short periods raise blood phosphorus rather than doing anything useful.

For anyone reading this page because of kidney disease, here is where the treatment evidence stands. A 2025 Cochrane review of 134 trials in 20,913 adults found phosphate binders brought no clear benefit for cardiovascular death or coronary artery calcium against placebo, on mostly low certainty evidence. On dialysis, sevelamer did beat calcium-based binders on deaths from any cause. Your own targets come from your clinician, and it is worth knowing they rest on thinner ground than the confidence of the advice suggests.

The number, and why it is softer than it looks

Established. Almost nobody in the United States is short of phosphorus. The middle of the distribution sits at 1,150 mg a day against a recommended 700, and among boys aged 14 to 18 the median is 1,444 mg. If you came here to find out whether you get enough, the answer for most readers is yes.

Europe publishes 550 mg a day for adults and calls it an Adequate Intake, which is the weaker of the two kinds of figure a regulator can issue. EFSA said why in plain words. The balance studies needed to work out how much phosphorus the body loses and how much of what you eat gets absorbed were judged insufficient, so no average requirement could be calculated. A figure arrived at that way describes what healthy people happen to eat.

Food reaches it without help. One cup of grated cheddar carries 517 mg, about three quarters of the American daily figure, and a cup of it melted carries 1,117 mg. A single 21 gram slice is 96 mg.

The part of your intake nobody can count

A Finnish survey found phosphate additives declared on one processed food in three, and European labelling rules make the manufacturer name the additive without ever saying how much went in. So the honest answer to how much phosphorus you eat has a hole in it, and the hole is widest in exactly the foods that carry the most.

What happens when the number goes up

Healthy young men with normal kidneys took an extra 750 mg of phosphorus a day in capsules for five days. Their blood phosphate rose from 0.87 to 1.00 mmol per litre, urinary phosphate nearly doubled, and the trialists called the change a possible health risk. That dose is the size an ordinary processed diet can carry, so this was not an exotic experiment. Separately, Europe set its first safety ceiling for phosphate additives in 2019, at 40 mg per kilogram of body weight a day, and estimated that infants, toddlers and children already reach it on average consumption.

Keep those two ceilings apart. One governs an additive and the other is a dietary reference value for the nutrient, and printing them side by side compares two different kinds of number.

One more thing about where these figures come from. Phosphorus appears in United States health claim law exactly once, and there it works as a restriction: a product carrying the calcium and osteoporosis claim may not contain more phosphorus than calcium by weight. In the European Union the same mineral has six authorised claims, one of them for maintaining normal bones. Whenever a page quotes a register at you, ask which register.

Not for everyone. If you take a phosphate supplement alongside cholestyramine or another bile acid binding resin, the label warns the supplement may be absorbed less well. Read that narrowly. It is a class warning carried over from a different drug rather than something measured on cholestyramine, and it belongs in a two-minute conversation with a pharmacist about timing.

Written from the evidence cards and the data on this page, then checked back against the sources. Bioma Learn has no human medical reviewer at this time and we say so rather than invent one. Information, not medical advice. How we verify.

Foods highest in phosphorus on this site

• Sunflower seed kernels, oil roasted — 1537.7 mg per 1 cup (123% DV)
• Sunflower seed kernels from shell, dry roasted — 1478.4 mg per 1 cup (118% DV)
• Pumpkin and squash seed kernels, roasted — 1385.3 mg per 1 cup (111% DV)
• Cheese spread, pasteurized process, American — 1225 mg per 1 cup, diced (98% DV)
• Pasteurized process cheese, American, low fat — 1157.8 mg per 1 cup, diced (93% DV)

All phosphorus sources ranked →

Full guide: Phosphorus: almost nobody is short of it, and the real question is your kidneys