Chapter 12. Micronutrients for Bones
Phosphorus
Role of Phosphorus
Phosphorus is a negatively charged intracellular electrolyte that is present in our bodies as part of a chemical group called a phosphate group. These phosphate groups are essential as a structural component of cell membranes (as phospholipids), DNA and RNA, energy production (ATP), and regulation of fluid balance and acid-base homeostasis. Phosphorus, however, is mostly associated with calcium as a part of the mineral structure of bones and teeth. Blood phosphorus levels are not controlled as strictly as blood calcium levels, as the PTH stimulates renal excretion of phosphate so that it does not accumulate to toxic levels.
Dietary Reference Intakes for Phosphorus
Unlike with calcium, most people are not at risk of a phosphate deficiency. The RDA is 700 milligrams per day. The UL set for phosphorous is 4,000 milligrams per day for adults and 3,000 milligrams per day for people over the age of seventy.
| Age Group | RDA (mg/day) | UL (mg/day) |
| Infants (0–6 months) | 100* | – |
| Infants (6–12 months) | 275* | – |
| Children (1–3 years) | 460 | 3,000 |
| Children (4–8 years) | 500 | 3,000 |
| Children (9–13 years) | 1,250 | 4,000 |
| Adolescents (14–18 years) | 1,250 | 4,000 |
| Adults (19–70 years) | 700 | 4,000 |
| Adults (> 70 years) | 700 | 3,000 |
| * denotes Adequate Intake | ||
| Data Source: (Phosphorous,” 2013)[1] | ||
Dietary Sources of Phosphorus
Phosphate is present in many foods popular in the North American diet including meat, fish, dairy products, processed foods, and beverages. Phosphate is added to many foods because it acts as an emulsifying agent, prevents clumping, improves texture and taste, and extends shelf-life.
| Foods | Serving | Phosphorus (mg) |
| Salmon | 3 oz. | 315 |
| Yogurt, nonfat | 8 oz. | 306 |
| Turkey, light meat | 3 oz. | 217 |
| Chicken, light meat | 3 oz. | 135 |
| Beef | 3 oz. | 179 |
| Lentils* | ½ c. | 178 |
| Almonds* | 1 oz. | 136 |
| Mozzarella | 1 oz. | 131 |
| Peanuts* | 1 oz. | 108 |
| Whole wheat bread | 1 slice | 68 |
| Egg | 1 large | 86 |
| Carbonated cola drink | 12 oz. | 41 |
| Bread, enriched | 1 slice | 25 |
| Data Source: (Phosphorous,” 2013)[2] | ||
Consuming Too Little Phosphorus
Phosphorus deficiency is rare, however, those who suffer from alcoholism, premature infants, the elderly with a poor diet, and those with a vitamin D deficiency may be at risk of low blood phosphorus levels.
Consuming Too Much Phosphorus
Phosphorus toxicity is rare, however, those with kidney disease or those who are taking too many vitamin D supplements or phosphorus-containing antacids may be at risk. Very high blood levels of phosphorus can result in muscle spasms and convulsions.
Phosphorus and Soft Drinks
Soft drinks contain a high amount of phosphoric acid and excessive intake of phosphoric acid may affect calcium metabolism which in conjunction with low calcium intake could result in decreased bone density, osteoporosis and increased fracture risk. [3] [4]
- Micronutrient Information Center: Phosphorus. Oregon State University, Linus Pauling Institute. http://lpi.oregonstate.edu/mic/minerals/phosphorus. Updated in July 2013. Accessed October 22, 2017. ↵
- Micronutrient Information Center: Phosphorus. Oregon State University, Linus Pauling Institute. http://lpi.oregonstate.edu/mic/minerals/phosphorus. Updated in July 2013. Accessed October 22, 2017. ↵
- Ahn and Parks., 2021. Sugar-sweetened beverage consumption and bone health: a systematic review and meta-analysis. Nutr J May 5;20(1):41. doi: 10.1186/s12937-021-00698-1. https://pubmed.ncbi.nlm.nih.gov/33952276/ ↵
- Chen, L. et al., 2020 High Consumption of Soft Drinks Is Associated with an Increased Risk of Fracture: A 7-Year Follow-Up Study. Nutrients Feb 19;12(2):530. doi: 10.3390/nu12020530 https://pmc.ncbi.nlm.nih.gov/articles/PMC7071508/ ↵
