Minerals, Supplements and Kidney Disease

Overview

Healthy kidneys balance salts and minerals in the blood. When kidney function falls, minerals such as potassium and phosphorus can build up. [2] This page explains the main minerals of concern and what the sources say. It does not tell anyone what to take. Limits for a person with CKD are set by their clinician using blood tests, the stage of disease and treatment. Evidence labels: established guidance (patient guidance from NIDDK, NHS or the National Kidney Foundation), review (a published review), and Proper evidence not found.

The minerals that matter most

Supplements and everyday products to check

• Potassium supplements and salt substitutes. NIDDK says salt substitutes can be high in potassium and to limit foods with potassium chloride on the ingredient list. [2] The NHS (UK) says older people should not take potassium supplements unless advised by a doctor, because their kidneys may be less able to remove potassium. [4] MedlinePlus lists poor kidney function, ACE inhibitors, ARBs and potassium-sparing diuretics among common causes of high blood potassium. [5]
• Phosphorus additives. NIDDK says to look for "phosphorus" or words with "PHOS" on ingredient lists, such as phosphoric acid and disodium phosphate. [2] The National Kidney Foundation says phosphorus from food additives is completely absorbed. [6]
• Magnesium products and antacids. The review says laxatives or antacids affect magnesium balance in dialysis patients. [3] MedlinePlus says magnesium excess most often occurs with magnesium supplements or magnesium-containing laxatives. [7]
• Phosphate binders. These are medicines, not supplements: NIDDK describes them as medicines that bind phosphorus from food in the stomach so it is not absorbed. [2] Use them only as prescribed.
• Herbal products. The National Kidney Foundation says "natural" does not always mean "safe" for people with CKD, and herbal supplements can worsen kidney disease or interact with prescribed medicines. [8]
• Calcium. MedlinePlus says higher calcium intake over a long period raises the risk of kidney stones in some people. [9] See Calcium supplements, heart disease and kidney stones.

Is a special diet needed?

The NHS says if you have CKD you may not need a special diet, and that a healthy, balanced diet can help. If blood tests show high potassium and phosphate, you may be referred to a dietitian. [1] Individual advice depends on stage, treatment and blood results.

Other situations to mention

Tell the kidney team about pregnancy or breastfeeding, a child with kidney disease, liver disease, planned surgery or dialysis, because each can change which supplements are suitable. See Supplements before surgery and Medication interactions.

Related pages

Existing conditions, Older adults and Mineral toxicity and upper limits.