Know About Phosphorus
by Mrs Meera Shah, Registered Dietitian, CDE
Phosphorus retention plays a very important role in the onset of mineral and bone disorders (MBD) in chronic kidney disease (CKD). There is a need for dietary phosphate control, but it is quite challenging in the real-life setting.
Phosphorus occurs in two forms:
- Organic phosphorus : They are Present Naturally in foods in form of phosphates ie
A)Plant based – Nuts, legumes, whole grains, beans
B)Animal based- Dairy products, meat, poultry, fish , egg yolk and seafood.
- Inorganic phosphorus (as salts) These food additives are added to foods to retain moisture for longer shelf life, and enhanced flavor. It is mostly added to meats, sausage, dark sodas such as cola, processed cheeses, chips, cookies, breads and baked goods, fast foods and many other pre-packaged foods.
Absorption of Phosphorus :
Absorption of Phosphorus varies in organic and inorganic food sources
|FOOD SOURCES||BIO AVAILABILITY|
|Food Additives||Very high|
Phosphorus is less absorbed from the plant based sources than the animal based sources. Plant based foods contain most of the phosphorus in form of phytic acid which is not available to the body and hence they contribute significantly low to serum Phosphorus compared to animal sources.
Phosphorus is 100% absorbed from the food additives. Inorganic phosphate additives have greater bioavailability than “organic” sources of phosphorus. Unfortunately all food products do not mention phosphorus content. One can read the ingredient list to check for the presence of phosphorus
One can check for the following phosphorus salts while checking the food ingredient list.
- Phosphoric Acid
- Dicalcium Phosphate
- Sodium Phosphate
Knowing the facts, some high phosphorus foods from plant based and Animal based sources cannot be avoided because of the need of high protein intake for dialysis patients . All high protein foods are high in phosphorus.
So to control serum phosphorus, one should take the following steps
- STOP Inorganic phosphorus (Food Additives)– First step should be to stop taking foods which are high phosphorus food additives rather than stopping high protein organic phosphorus
- Take a Phosphate Binder– Even after restricting high phosphorus food additives, serum Phosphorus does not appear normal, then a Phosphate binder should be the consumed in between the meals as prescribed by a doctor.
There are three 3 types of phosphorus binder
- A) Aluminium Hydroxide Aluminium hydroxide has an excellent phosphate-binding capacity.
Disadvantages- Dementia, osteomalacia, anaemia
B) Calcium based Phosphorus binder – Calcium Carbonate
It can increase serum calcium levels leading hypercalcemia especially when it is combined with Vitamin D Therapy. Sometimes, calcium also get deposited in the blood vessels causing calcification.
C) Non calcium based Phosphorus Binder– They are generally advised to Dialysis patient.
- Sevelamer hydrochloride– Sevelamer : It is the most commonly prescribed non-calcium-based phosphate binder, but has a lower phosphate-binding capacity than other phosphate binders.
Disadvantages – High pill burden, expensive, reduce the bioavailability of fat- soluble vitamins, gastrointestinal intolerance and metabolic acidosis.
- Lanthum carbonate : It is roughly twice as potent as calcium and sevelamer. It reduces the pill burden.
Diadvantages -Gastrointestinal intolerance, particularly nausea and expensive.
- C.Sucroferric Oxyhydroxide : It is an iron-based phosphate binder,expensive
- Restrict Plant based and animal Based high phosphorus Foods –Patients can work with a renal dietitian to get your diet plan based on your preferences, religion and economic status.