B vitamins are water-soluble, which means they are filtered by the kidneys and lost more easily during dialysis. They also play a role in homocysteine metabolism — a marker linked, though not conclusively, to cardiovascular risk in CKD.
What the NHS says about B vitamins
For most UK adults with healthy kidneys, a varied diet that follows the Eatwell Guide provides enough B vitamins, with two notable exceptions:
Folic acid: women planning pregnancy or in the first 12 weeks of pregnancy should take 400 µg daily.
Vitamin B12: people on a strict vegan diet or with pernicious anaemia need a supplement or fortified foods.
B vitamins in CKD
People on dialysis often lose water-soluble vitamins through the dialysate, and renal-specific multivitamins (such as Renavit) are commonly prescribed in the UK. They contain B1, B2, B6, B12, folic acid, niacin, biotin, pantothenic acid and vitamin C in renal-appropriate doses.
For people with non-dialysis CKD, large doses of B vitamins are not routinely recommended. A high-quality 2010 trial published in JAMA found that high-dose folic acid, B6 and B12 in CKD did not reduce vascular events — and may even have increased risk of decline in kidney function.
Practical takeaways
Eat wholegrains, pulses, eggs, dairy and lean meat for natural B vitamins.
If you are on dialysis, take any renal multivitamin your team has prescribed.
Avoid mega-dose B-complex products bought online unless your renal team has explicitly recommended them.
Why the kidneys need B vitamins
Water-soluble B vitamins (B1 thiamine, B2 riboflavin, B6 pyridoxine, B12 cobalamin, folate, niacin, pantothenic acid and biotin) are not stored in the body. They are also dialysed out during haemodialysis, which is why renal multivitamins like Renavit are routinely prescribed for dialysis patients.
Typical UK doses
Thiamine (B1): 1.0–1.4 mg/day
Riboflavin (B2): 1.1–1.3 mg/day
Pyridoxine (B6): 1.2–10 mg/day (higher in dialysis)
Folic acid: 200–1000 µg/day
B12: 1.5–4 µg/day, higher if deficient
Practical UK checklist for B Vitamins and Kidney Health: What the UK Evidence Shows
Know your numbers. Ask your GP for your most recent eGFR, urine ACR, blood potassium, phosphate, bicarbonate and 25-OH vitamin D.
Audit what you already take. Lay every supplement, herbal product and sports nutrition pot on the kitchen table. List actives by dose, not by %NRV.
Cross-check against UK guidance. NICE NG203 for CKD, NG118 for stones, NG136 for hypertension; NHS condition pages for general nutrition.
Book a pharmacist medicines review. Free on the NHS in England (the New Medicine Service and Structured Medication Reviews) and in equivalent schemes across Scotland, Wales and Northern Ireland.
Re-evaluate every 3–6 months. Kidney function changes; what was right last year may not be right today.
Common myths vs UK clinical reality
Myth: 'Kidney cleanses flush toxins.' Reality: The kidneys are the cleansing organ; no UK clinical body endorses 'cleanse' supplements, and several have caused acute kidney injury.
Myth: 'More vitamins is always better.' Reality: High-dose vitamin A, vitamin C and selenium are linked to harm in CKD; safety lies inside the UK RNI ranges.
Myth: 'Natural means safe.' Reality: Several herbals (Aristolochia, high-dose liquorice, comfrey) cause kidney injury. Look for MHRA Traditional Herbal Registration (THR) marks.
Myth: 'Drink as much water as possible.' Reality: Pale-straw urine is the goal in early CKD; advanced CKD and dialysis often require fluid restriction.
Common mistakes UK kidney patients make with supplements
Reaching for a standard high-street multivitamin. Most contain retinol vitamin A and sometimes added potassium or phosphate — fine for the general population, not ideal in CKD.
Using "low-sodium" salt as a swap. LoSalt, Solo and similar products are mostly potassium chloride, which can be dangerous in CKD, on ACE inhibitors, ARBs or potassium-sparing diuretics.
Buying a "kidney cleanse" or "renal detox" blend. No UK clinical body endorses these; several have caused acute kidney injury.
Stacking single-nutrient mega-doses. Three separate "high-strength" pots often deliver three times the safe ceiling for vitamin A, selenium or zinc.
Stopping prescribed renal vitamins (Renavit) and replacing them with a supermarket multivitamin. Renavit is designed for dialysis losses; over-the-counter products are not.
Forgetting to mention supplements at GP and pharmacy reviews. Interactions with warfarin, tacrolimus, ciclosporin and SGLT2 inhibitors are common and easy to miss.
How this fits into UK kidney care
Routine NHS kidney monitoring in adults uses two simple tests: serum creatinine (used to calculate eGFR) and a urine albumin-to-creatinine ratio (ACR). NICE NG203 sets out how often these should be repeated by stage, and when to refer to a renal team. Charities such as Kidney Care UK and the National Kidney Federation publish UK-specific patient information that complements anything you read in this guide.
When to speak to your GP
Persistent foamy urine, swollen ankles or unexplained fatigue.
An eGFR below 60 mL/min/1.73 m² on two tests at least 90 days apart.
Considering any new supplement when you have CKD, are on dialysis, or have had a transplant.
A family history of kidney disease, diabetes or high blood pressure under 50.
Medically reviewed for UK patients. This Q&A is general information, not a replacement for personal advice from your GP, renal team or registered dietitian.
In plain English, what is this guide on "B Vitamins and Kidney Health" actually telling me?
Folate, B12, B6 and the rest — what the UK NHS and SACN say about B vitamins for kidney health and homocysteine in CKD. The short version: read this whole page if b vitamins and kidney health is directly relevant to you, and use the TL;DR box at the top if you only have a minute.
Is b vitamins and kidney health safe for me if I have kidney disease?
B vitamins at the doses found in a standard UK multivitamin are safe for most people. If you are on dialysis, your renal team will usually prescribe a renal-specific multivitamin (such as Renavit) instead — because dialysis washes out water-soluble B vitamins. The detail on how this specifically applies to b vitamins and kidney health is in the deep-dive section above.
How much should I have, and how often?
The page above gives UK-specific doses, portion sizes or frequencies. If you have CKD, are on dialysis, are pregnant, are over 65, or take regular medication, treat those numbers as a starting point and confirm them with your GP, pharmacist or renal dietitian before changing anything.
Will b vitamins and kidney health interact with my usual medicines?
Common UK medicines that interact with supplements and foods include warfarin, ACE inhibitors (ramipril, lisinopril), ARBs (losartan, candesartan), diuretics (furosemide, spironolactone), PPIs (omeprazole, lansoprazole), metformin, statins and immunosuppressants (tacrolimus, ciclosporin). If you take any of these, ask your community pharmacist for a free Medicines Use Review before adding anything new.
What should I look for on the UK label or menu?
For supplements: check the actives table for the dose (not just %NRV), scan the 'other ingredients' line for added potassium chloride, phosphate salts or hidden sodium bicarbonate, and prefer beta-carotene over retinol. For food: check the back-of-pack salt (red traffic light is over 1.5 g per 100 g) and the additives list for phosphate codes E338–E452.
When should I actually speak to my GP or kidney team?
Speak to your GP if you have new ankle swelling, foamy urine, blood in the urine, unexplained tiredness, an eGFR below 60 on two tests 90 days apart, or before starting any new supplement when you already have CKD, are on dialysis, or have had a transplant.
Frequently asked questions
Do I need B vitamins on dialysis?
Yes. UK renal centres typically prescribe Renavit or an equivalent because dialysis removes water-soluble B vitamins.
Is folic acid safe in CKD?
Yes, at typical UK doses (200–400 µg/day). Higher doses are used in specific anaemia protocols under specialist care.
Should I take B12 with CKD?
Routine B12 supplementation is not needed unless deficiency is confirmed, more common in older adults and vegans.
Can B6 damage the kidneys?
No, but very high B6 (>200 mg/day) long-term can cause nerve problems unrelated to the kidneys.
What is the difference between Renavit and a regular multivitamin?
Renavit has higher water-soluble B vitamins and no fat-soluble vitamins, which suits dialysis patients.
Kidney Vitality is a daily multivitamin developed by a UK Consultant Nephrologist using renal nutrition principles. It contains no added potassium, magnesium, phosphorus or iron, and no herbal blends. See the formulation.
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.
✓ Free UK tracked delivery · ✓ Delivered every 30 days · ✓ Pause or cancel anytime · ✓ Never run out
Comparison
Kidney Vitality
Typical high-street multivitamin
Added potassium
None
Often included
Added phosphate
None
Often included (E338–E452)
Vitamin A (retinol)
No megadose
Often high-dose retinol
Kidney-focused formulation
Yes
No — general population
Consultant Nephrologist involvement
Yes (GMC 7216325)
No
UK GMP manufactured
Yes (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
MA
Professor Mohammed Mahdi Althaf
Consultant Nephrologist
Acute Physician
GMC 7216325
View Full BiographyHide 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.
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 processHide 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.
This content is educational only and does not replace personalised medical advice.
Read full disclaimerHide 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, diet or lifestyle change with your GP, pharmacist, renal dietitian or nephrologist before starting.
Kidney Vitality is a food supplement and is not intended to diagnose, treat, cure or prevent any disease. Always read the label and seek personalised advice from a UK-registered healthcare professional who knows your medical history.
