Kidney Diet 7 min read·Updated 22 July 2026 Clinician-reviewed

Is Marmite Bad for Your Kidneys?

A UK Consultant Nephrologist on Marmite in chronic kidney disease — why the salt content matters more than the B vitamins.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 22 July 2026

Professor Mohammed Mahdi Althaf

Consultant Nephrologist & Acute Physician

View Credentials

Professor Mohammed Mahdi Althaf

MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN

Consultant Nephrologist & Acute Physician · GMC 7216325

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Direct answer

Marmite is one of the saltiest spreads in UK supermarkets at 10.8 g salt per 100 g. A thin scraping on toast adds 0.3 g salt — manageable occasionally. Daily use, or thick spreading, can easily push someone with CKD over their sodium budget. Marmite Reduced Salt or nutritional yeast are better choices.

Key recommendation: Marmite: 10.8 g salt per 100 g (highest common UK spread).

Quick answer

✓ Best choices

  • Vegetables and lower-potassium fruit at every meal
  • Whole grains: oats, basmati rice, pasta, wholegrain bread
  • Lean protein in modest portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil, herbs and spices for flavour

✓ Foods to limit

  • Added salt and salty sauces
  • Processed meats and foods with phosphate additives (E338–E452)
  • Very large portions of bananas, oranges, potatoes if potassium is rising

Key takeaway

Marmite is one of the saltiest spreads in UK supermarkets at 10.8 g salt per 100 g. A thin scraping on toast adds 0.3 g salt — manageable occasionally. Daily use, or thick spreading, can easily push someone with CKD over their sodium budget. Marmite Reduced Salt or nutritional yeast are better choices.

Who should be cautious

People on dialysis, post-transplant, pregnant or breastfeeding, or taking prescription medication — confirm with your renal team before changes.

Is Marmite Bad for Your Kidneys?

Why Marmite is so salty

Marmite is made by concentrating brewer's yeast extract with added salt. The salt is both flavour and preservative. At 10.8 g salt per 100 g, it sits at the very top of the UK spread league — higher than soy sauce per gram. Bovril (beef extract) is similar at ~10 g salt per 100 g. The saving grace is that a typical 'scraping' is only 2–3 g, not the 10 g portion size you'd use for jam or butter.

How much is too much in CKD?

NICE NG203 recommends ≤ 6 g salt per day for CKD. A 3 g Marmite scraping (0.3 g salt) is 5% of that budget — fine as an occasional treat. Two slices of toast with Marmite plus a slice of ham at lunch can easily reach 3–4 g salt — more than half the daily limit before dinner. Use Marmite sparingly, on toast made from lower-salt bread (or unsalted oatcakes), and skip salty fillings the rest of the day.

Food first. If you are choosing a daily multivitamin alongside a balanced diet, Kidney Vitality was developed by a UK Consultant Nephrologist using renal nutrition principles. See the formulation.

B vitamins — is it worth it?

A 5 g serving of Marmite provides ~30% of daily B1, ~30% B2, ~30% B3, ~25% B6, ~70% folate (B9) and ~70% B12. For dialysis patients, B-vitamin needs are higher and water-soluble vitamins are lost through the dialyser. But the salt load makes Marmite a poor primary B-vitamin source. A renal-friendly B-complex supplement (or prescribed Renavit/Dialyvit) delivers the same vitamins with no salt.

Reduced Salt Marmite

Marmite Reduced Salt cuts sodium by about a third (to ~7.1 g salt per 100 g). It's the easiest direct swap for Marmite fans with CKD. Available in most major UK supermarkets in the spreads aisle. Same flavour profile, same B-vitamin fortification, two-thirds of the salt.

Nutritional yeast — the renal-friendly swap

Nutritional yeast flakes (Engevita, Marigold) deliver the same umami / 'cheesy' flavour, are sodium-free, and are usually fortified with B12. Sprinkle on toast, eggs, pasta or soup. 5 g (1 tbsp): ~20 mg sodium, ~120 mg potassium, ~80 mg phosphate, and a good dose of B vitamins. A genuinely renal-friendly substitute for both Marmite and grated parmesan.

Is Salt Bad for Your Kidneys?
Related reading: Is Salt Bad for Your Kidneys?.

Key practical tips

Designed for quick scanning — what to order, what to avoid, sensible portions, common mistakes.

  • Read labels: sodium ≤ 0.3 g per 100 g (low) is the target
  • Cook from scratch when you can — it controls the hidden salt and phosphate
  • Personalise potassium and phosphate targets with your renal dietitian

Clinical guidance

TL;DR summary

Marmite is one of the saltiest spreads in UK supermarkets at 10.8 g salt per 100 g. A thin scraping on toast adds 0.3 g salt — manageable occasionally. Daily use, or thick spreading, can easily push someone with CKD over their sodium budget. Marmite Reduced Salt or nutritional yeast are better choices.

Key takeaways
  • Marmite: 10.8 g salt per 100 g (highest common UK spread).
  • 3 g scraping: ~0.3 g salt, ~63 mg potassium, ~23 mg phosphate.
  • Reduced Salt Marmite: ~7.1 g salt per 100 g.
  • Fortified with B1, B2, B3, B6, B9 and B12.
  • Nutritional yeast: similar umami, sodium-free, B-vitamin rich.
Kidney Diet & Nutrition Considerations

On a kidney-friendly diet, single foods matter less than the overall pattern. Build meals around vegetables, lower-potassium fruit, whole grains, sensible protein and olive oil, and watch the three usual suspects — salt, phosphate additives and oversized portions of very high-potassium foods. Targets are individual and should be confirmed with your renal team.

Foods to prioritise

  • Vegetables and lower-potassium fruit at every meal
  • Whole grains: oats, basmati rice, pasta, wholegrain bread
  • Lean protein in modest portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil, herbs and spices for flavour

Foods to limit

  • Added salt and salty sauces
  • Processed meats and foods with phosphate additives (E338–E452)
  • Very large portions of bananas, oranges, potatoes if potassium is rising

Potassium, phosphate and protein needs vary between individuals — please confirm personal targets with your renal team or dietitian. Browse the Kidney Diet Hub for more guides in this cluster.

Frequently asked questions

Is Marmite bad for kidneys?

Marmite is extremely high in salt — 10.8 g salt per 100 g, the highest of any common UK breakfast spread. A scraping on toast (3 g) adds about 0.3 g salt. People with CKD should treat Marmite as an occasional flavour boost, not a daily habit.

How much salt is in Marmite?

Standard Marmite: 10.8 g salt per 100 g (4.3 g sodium per 100 g). A 3 g scraping: 0.32 g salt. A 5 g teaspoon: 0.54 g salt. Marmite Reduced Salt: ~7.1 g salt per 100 g — still high, but a third lower.

Does Marmite have potassium or phosphate?

Yes — Marmite contains ~2,100 mg potassium per 100 g and ~770 mg phosphate per 100 g, both naturally from yeast. A 3 g scraping adds ~63 mg potassium and ~23 mg phosphate. Modest at a small portion, but adds up if used heavily.

Is the B-vitamin content useful for CKD?

Marmite is fortified with B vitamins (B1, B2, B3, B6, B9, B12). A serving covers a meaningful fraction of daily B-vitamin needs. However, the salt load usually outweighs this benefit — better to take a renal-friendly B-complex supplement and skip the salt.

What is a renal-friendly alternative to Marmite?

Marmite Reduced Salt is the most direct swap. Other options: nutritional yeast flakes (sodium-free, umami flavour, also B-vitamin fortified), or low-sodium yeast extracts now stocked in some health food stores.

What foods are best for kidney health?

A kidney-friendly diet centres on vegetables, lower-potassium fruit (apples, pears, berries), whole grains (oats, basmati rice, pasta), sensible portions of fish, eggs or lean meat, beans and lentils in modest portions, and olive oil as the main cooking fat — broadly a Mediterranean pattern with reduced salt.

Nutritional challenges in kidney disease

Many people living with kidney disease have to limit foods because of potassium, phosphate, diabetes, dialysis, appetite changes or simply the time it takes to cook from scratch every day. That can make it harder to keep daily nutrition balanced — particularly for vitamins and minerals that food alone may not fully cover.

Kidney Vitality is a UK-formulated daily nutritional support product designed by Consultant Nephrologist Professor Mohammed Mahdi Althaf with renal nutrition in mind from the start. It keeps doses moderate, leaves out added potassium, phosphate and magnesium, and avoids megadose vitamin A — sitting alongside a kidney-friendly diet, not replacing it.

Why Kidney Vitality fits this need

Built around UK renal guidance

Aligned with NICE NG203, KDIGO 2024 and BDA renal nutrition guidance on sodium and B-vitamin needs in CKD.

Designed by a UK Consultant Nephrologist

Formulated and reviewed by Professor Mohammed Mahdi Althaf (GMC 7216325).

Evidence-based by design

No added potassium or phosphate; sensible B-vitamin doses without the salt load.

Designed by a UK Consultant Nephrologist

Ready to support your kidney health?

If you have been researching kidney health, supplements, CKD nutrition or kidney-friendly living, Kidney Vitality was developed specifically around those principles by Professor Mohammed Mahdi Althaf (GMC 7216325). Nephrologist Developed Daily Multivitamin.

  • No Added Potassium
  • No Added Phosphorus
  • No Added Iron
  • UK Manufactured
  • One capsule daily
  • UK GMP — BRCGS, NSF GMP, Halal
Subscribe & Save — £20.39/monthCheck your current multivitamin

✓ Free UK tracked delivery  ·  ✓ Delivered every 30 days  ·  ✓ Pause or cancel anytime  ·  ✓ Never run out

ComparisonKidney VitalityTypical high-street multivitamin
Added potassiumNoneOften included
Added phosphateNoneOften included (E338–E452)
Vitamin A (retinol)No megadoseOften high-dose retinol
Kidney-focused formulationYesNo — general population
Consultant Nephrologist involvementYes (GMC 7216325)No
UK GMP manufacturedYes (BRCGS, NSF GMP)Varies

Food supplement. Not a medicine and not a treatment for kidney disease. Speak with your GP, pharmacist or renal team before starting any new supplement, especially in advanced CKD, on dialysis, post-transplant, pregnant or breastfeeding.

Clinical reviewer

Professor Mohammed Mahdi Althaf

Consultant Nephrologist

Acute Physician

GMC 7216325

View Full Biography

Professor Mohammed Mahdi Althaf is a UK Consultant Nephrologist and Acute Physician with a special interest in chronic kidney disease, AKI prevention and renal nutrition. He combines hospital practice with patient education and clinical guidance review.

View professional profile →
View Credentials
  • MD
  • MSc
  • PgDip (Clin Ed)
  • FRCP
  • FHEA
  • FASN

About this article

Written for UK patients and based on:

  • NICE guidance
  • NHS resources
  • British Dietetic Association guidance
  • Kidney Care UK resources
View methodology

Each article is researched against current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO and KDOQI international guidelines, and the British Dietetic Association Renal Nutrition Group. Drafts are written by the Kidney Vitality editorial team and reviewed by a UK Consultant Nephrologist before publication. Content is reviewed on a rolling basis and updated when guidance changes.

Editorial standards

  • Clinically reviewed
  • NHS-aligned
  • NICE-aligned
  • Evidence-based
  • Reviewed before publication
View full editorial process

Every article is researched and written by the Kidney Vitality editorial team using current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO/KDOQI international guidelines, and British Dietetic Association renal nutrition guidance. Drafts are reviewed for clinical accuracy by Professor Mohammed Mahdi Althaf, MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN (Consultant Nephrologist & Acute Physician, GMC 7216325) before publication. Content is updated when UK guidance changes.

References (4)View Sources
  1. NICE NG203: Chronic kidney disease — assessment and management
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
  3. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update
  4. British Dietetic Association — Renal Nutrition Group

Medical disclaimer

This content is educational only and does not replace personalised medical advice.

Read full disclaimer

This page is general information, not personal medical advice. If you have chronic kidney disease, are on dialysis, have had a kidney transplant, are pregnant or breastfeeding, or take prescription medication, please confirm any supplement with your GP, pharmacist or renal team before starting.

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