Phosphorus

Adults need 550 milligrams of phosphorus per day. You should be able to get all the phosphorus you need from your daily diet.

The 2003 National Diet and Nutrition Survey found that average daily intakes of phosphorus from food were 1112 milligrams for women and 1493 milligrams for men.  That’s 202 per cent and 271 per cent of the recommended amount for women and men respectively. Overall, no men and less than 0.5 per cent of women had an intake of phosphorus below the lower recommended level. These intakes had increased since the previous survey in 1986/7. It seems likely that intakes may have increased further given the prevalence of phosphorus in processed foods.

Phosphorus is necessary for healthy bones and teeth, it’s an essential component of all our cells and genetic information (DNA and RNA) and is important for maintaining the right chemical balance (pH) in the body. Phosphorus is also essential for energy metabolism and for the release of energy from food.

High intakes of phosphorus may affect calcium metabolism and its hormone control so it’s advisable to watch your intake – fizzy drinks can contain large amounts if they’re made with phosphoric acid.

Taking high doses of phosphorus in supplements can cause diarrhoea or stomach pain and if you take high doses in the long term, it can lead to calcium loss and weakened bones. Taking up to 250 milligrams a day on top of dietary intake (ie in addition to the estimated maximum intake of phosphorus from food of 2110 milligrams per day) is unlikely to cause any harm.

No, a healthy vegan diet containing the above foods on a daily basis will cover your needs.

The best plant sources of phosphorus include nuts (peanuts, peanut butter, almonds, Brazil nuts, cashew nuts, pecan nuts, hazelnuts/filberts and walnuts) wholegrains (quinoa, wholemeal spaghetti, wholegrain rice, oatmeal or rolled oats, wheatgerm, oatcakes and wholemeal bread) pulses (tofu, tempeh – fermented soya beans, lentils, edamame, peas and chickpeas), seeds (pumpkin seeds, sesame seeds and tahini – sesame seed paste and sunflower seeds), corn on the cob and parsnips.

loss of appetite, anxiety, bone pain, fragile bones, fatigue, irregular breathing, irritability, joint stiffness, numbness, weakness, in children – slower growth and poor bone and tooth development.

Source: Public Health England: McCance and Widdowson’s The Composition of Foods Integrated Dataset.

Along with calcium, phosphorus is needed to build strong healthy bones. Around 80 per cent of the phosphorus in our bodies is found in the skeleton, the remainder is in our soft tissues and extracellular fluid.

Typical Western diets tend to be high in phosphorus due to high content in meat, dairy, nuts and other foods rich in protein. The amount of phosphorus in Western diets is further increased by its use in preservatives added to processed foods and fizzy drinks. Plant-based proteins (nuts and seeds) may be richer in phosphorus compared to animal proteins, however, the phosphate in plant proteins is only 30-50 per cent bioavailable, while that in animal proteins (milk and cheese), is estimated to be 70-80 per cent bioavailable. So, it’s not a good idea to eat more protein than you need.

Low calcium/high phosphorus diets contribute to bone disease

Phosphoric acid (containing phosphorus) is used as a preservative in a variety of fizzy drinks such as Coca‑Cola, Diet Coke, Coke Zero and Dr Pepper. Research shows that these drinks may cause bone loss in older women. The phosphoric acid (and sugar) may be to blame, or it may be that these drinks are drunk in place of healthier calcium-containing drinks such as calcium-fortified soya milk.

The effects of high phosphate levels are difficult to distinguish from those of low calcium and it has been argued that high phosphate levels may not have adverse effects on bone if calcium intakes are adequate.

Bones serve as a reservoir of calcium in the body. High levels of phosphorus in the diet can result in calcium being pulled from the bones as the body attempts to balance out the effect of phosphates in the blood. Low levels of calcium and vitamin D make the situation worse. Black and Asian people and older people may be more vulnerable to this type of bone loss as a result of high phosphorus intakes, as they are more susceptible to deficiency in vitamin D (deficiency of vitamin D decreases calcium absorption).

Kidney disease

Your kidneys help control the amount of phosphate in the blood. Excess phosphate that the body does not need is filtered out of the blood by the kidneys and passed in the urine. Excessively high levels of phosphorus in the blood are rare but may occur in people with kidney disease (who are unable to excrete excess phosphorus in the urine). In such cases, phosphorus may combine with calcium to form deposits in soft tissues such as muscle. Some evidence suggests that this may increase the risk of cardiovascular disease. People with kidney disease can reduce the content of phosphorus in food by boiling it before eating it and avoiding phosphorus additives.