Phosphorus
Also known as Phosphate
Phosphorus is the second most abundant mineral in the body after calcium, with about 85 percent found in bones and teeth as calcium phosphate. It is a core component of DNA, RNA, cell membranes, and the energy molecule ATP, and it helps regulate acid-base balance. Phosphorus is widespread in the food supply, so dietary deficiency is rare in healthy people.
The recommended intake sits at about 18% of the level considered the safe daily ceiling, leaving comfortable headroom.
Why it matters
What it does in your body
- Bone and teeth mineralization
- Energy storage and transfer as ATP
- DNA and RNA structure
- Cell membrane phospholipids
- Acid-base balance
By age, sex, and life stage
How much you need
Values are RDAs except for infants, which are AI values. The RDA is high at 1250 mg during ages 9 to 18 for skeletal growth, then drops to a flat 700 mg for all adults 19 and older, with no increase for pregnancy or lactation.
Recommended intake across life
in mg/dayBars scale to the highest recommendation shown. Where men and women differ, both values are listed.
Full reference table
| Life stage | Male | Female |
|---|---|---|
| Infants 0-6 mo | 100 (AI) | 100 (AI) |
| Infants 7-12 mo | 275 (AI) | 275 (AI) |
| Children 1-3 | 460 | 460 |
| Children 4-8 | 500 | 500 |
| Children 9-13 | 1250 | 1250 |
| Teens 14-18 | 1250 | 1250 |
| Adults 19-50 | 700 | 700 |
| Adults 51-70 | 700 | 700 |
| Adults 71+ | 700 | 700 |
| Pregnancy | n/a | 700 to 1250 |
| Lactation | n/a | 700 to 1250 |
Values in mg/day. AI marks an Adequate Intake, used when there is not enough evidence for a formal recommendation.
What moves the number
What changes your needs
Age
Needs spike to 1250 mg during ages 9 to 18 to support rapid bone growth, then settle to 700 mg for all adults; the UL is lowered after 70.
Sex
Requirements are identical for males and females at every life stage; there is no sex-based difference in the RDA.
Body weight / size
Phosphorus is set by life stage rather than body weight, but people with chronic kidney disease must limit intake regardless of size because they cannot clear excess phosphate.
Pregnancy and lactation
The RDA does not rise above the nonpregnant value, as absorption adapts to demand; pregnant and lactating teens need 1250 mg and adults 700 mg.
Running low
Signs you might not get enough
Most at risk: Preterm newborns, people with genetic phosphate-wasting disorders, and severely malnourished patients at risk of refeeding syndrome are the main groups affected.
Too much
Can you get too much?
High phosphorus intake rarely harms healthy people, but those with chronic kidney disease cannot excrete excess and are at real risk. Phosphate additives in processed foods and colas add a highly absorbable, often unlabeled, load.
Where to get it
Best food sources
The bottom line
Most people easily meet the 700 mg adult target from dairy, meat, fish, poultry, and legumes, so supplements are rarely needed. The real concern is excess for people with kidney disease and the hidden phosphate additives in processed foods and sodas.
Track phosphorus automatically
Phosphorus is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.
Sources and method
The recommended intakes, upper limits, and food-source amounts on this page come from the primary references below. Numbers were checked against the current NIH Office of Dietary Supplements fact sheets and the Institute of Medicine (now the National Academies) Dietary Reference Intakes.
- NIH Office of Dietary Supplements, Phosphorus Fact Sheet for Health Professionals
- Institute of Medicine (1997), Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride
This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.