Renal - Controlling your phosphate intake

What are Phosphate and Calcium?

Phosphate and calcium are minerals that come from the food you eat. They work together to keep your bones, teeth, heart and blood vessels healthy.

Why is the phosphate level in my blood high?

Your kidneys help to control the levels of phosphate and calcium in your body. When your kidneys are not working properly, too much phosphate can build up in the blood.

Why is it important to control my phosphate levels?

When you have too much phosphate in your blood it causes your body to take calcium from your bones to try and keep your blood balanced. This can lead to weakening of your bones and a build- up of calcium in blood vessels.

If your levels of calcium and phosphate go too high in your blood, then this can cause serious problems.

Symptoms of a high blood phosphate level:

• Itchy skin and eyes
• Weak bones that may break more easily
• Bone and joint pain
• Muscle weakness and problems walking
• Cold, tingling hands and feet

What are the long-term effects?

If high levels of blood phosphate continue, calcium and phosphate can join together to form hard deposits. This is called ‘calcification’.

• These deposits can form in the heart, lungs, blood vessels, joints and skin
• This can lead to an increased risk of heart disease and stroke
• This can put your chances of having a transplant at risk

You may not feel any symptoms of high phosphate levels, however serious problems may be occurring.

What phosphate levels should I be aiming for?

The aim of treatment is to maintain blood phosphate levels as follows:

Not on dialysis 0.9-1.5mmol/l

When on dialysis 1.1 – 1.7 mmol/l

How can I control the level of phosphate in my blood?

1. Reduce the amount of phosphate in your diet
2. Take your ‘phosphate binder’ medication (if prescribed)

Which foods contain phosphate?

There are two types of phosphate in food:

• Phosphate additives – around 90 – 100% absorbed by the body
• Natural phosphates – around 50% absorbed by the body

Phosphate additives

Manufacturers add phosphate additives to lots of different foods. This means you could be eating more phosphate than you realise.

Phosphate additives have more effect on your blood phosphate level than natural phosphates.

Common reasons for adding phosphate to food include:

• To keep food moist
• To improve the taste and texture of food
• To extend the ‘use by date’ of food

Natural phosphates

• Some foods are naturally high in phosphate
• About half of the phosphate in these foods is absorbed by the body
• These tend to be protein foods (meat, fish, dairy, and eggs)
• They are needed for growth, repair and healing
• Different amounts of protein are needed depending on your stage of kidney disease and treatment type. Ask your dietitian for more information

Hints and tips for avoiding phosphate additives

• Choose fresh meat, poultry and fish where possible
• Choose the best quality meat or fish you can within your budget
• Use dried rice and pasta rather than buying pre-cooked
• Cook with fresh ingredients to reduce your phosphate additive intake
• Try making your own sauces rather than using pre-prepared jars or packets
• Cook large quantities of meals from fresh ingredients to give you a tasty, additive free meal, then freeze the leftovers - saves time and money too!
• Make your own mash, roast and chipped potatoes. Try not to use frozen or prepared potato products
• Fast food contains phosphate additives, so limit to an occasional treat

Food labelling – how to find out if a food has phosphate additives

Manufacturers are not legally required to state the phosphate content of food on the label. Looking out for some ingredients will help you to know which foods contain phosphate additives. These foods should be limited.

The phosphate additive may be listed by its full name or E number.

As a general rule, look for ingredients with “PHOS” in the name.

Lots of different phosphate additives are used. Try to limit all phosphate additives in the diet. Some have a bigger effect on your blood phosphate level than others. Listed below are the additives that have the biggest effect on your blood phosphate level. These should be avoided.

For example, these are the ingredients for an instant coffee latte drink: Sugar, Skimmed Milk Powder, Glucose Syrup, Coconut Oil, Coffee, Lactose, Natural Flavourings, Salt, Acidity Regulator (E340), Stabilisers (E331, E452) If the phosphate additive is listed by its chemical name it may be easier to look for an ingredient that includes the letters ‘phos’, e.g. these are the ingredients for a honey roast ham: Pork (96%), Honey (4%), Salt, Sugar, Stabilisers: Triphosphates; Antioxidant:Sodium Ascorbate; Preservative: Sodium Nitrite.

Phosphate in foods

This leaflet provides more information on foods from both the naturally high phosphate and phosphate additives groups. It gives examples of lower phosphate foods and can help you to choose the foods that you enjoy, whilst keeping your phosphate well controlled.

Phosphate is found in large amounts in dairy foods and most protein foods e.g. meat, poultry, fish, eggs and pulses. These foods can still be included as they are an important source of protein, vitamins and minerals.

The following tables show you how best to include these foods as part of a balanced diet and gives recommended allowances.

• Always consider any other dietary needs such as diabetes, low salt, low potassium, allergies or intolerances when making your choices. Discuss any queries or concerns with your dietitian
• If you have a poor appetite or are eating less than usual, please contact your dietitian before following this advice

• If you are vegetarian or vegan continue having beans and lentils as usual
• Nuts are high in phosphate but are also a good source of protein. If you follow a vegetarian or vegan diet, you can still include small quantities of nuts in your diet. Discuss with your dietitian

*(14 units a week 1 – 2 drinks per day. 25ml = 1 unit)

Phosphate Binders

In addition to limiting the amount of phosphate in your diet, you may also be prescribed some tablets known as phosphate binders.

These tablets act like a sponge and bind with some of the phosphate in your food to stop it being absorbed into your body. They cannot remove all of the phosphate in your food, so some dietary restriction will be needed.

If needed, phosphate binders are prescribed by your doctor. They are usually taken with all meals containing phosphate. Your dietitian can give you more advice on when and how to take phosphate binders.

Further information about controlling your phosphate level is available from your dietitian.

Name:

Dietitian:

Telephone 0161 206 1994
Email: renaldietitians@nca.nhs.uk

Useful links

These links have information on phosphate including meal ideas and recipes to try. They also provide general advice on living with kidney disease.
www.kidneycareuk.org
www.kidney.org.uk
https://kinet.site/gmkin/ (Greater Manchester Kidney Information Network)