High blood pressure is the second most common cause of kidney failure in the UK after diabetes, and salt is one of the biggest dietary drivers of high blood pressure. The UK target is straightforward: no more than 6 g of salt a day for adults — equivalent to about 2.4 g of sodium.
Where the salt actually comes from
Action on Salt and the Food Standards Agency estimate that around 75% of the salt we eat in the UK is already in the food when we buy it, not added at the table. The biggest contributors are bread, processed meats (bacon, ham, sausages), cheese, breakfast cereals, ready meals and sauces.
Reading UK food labels
High in salt: more than 1.5 g salt per 100 g (red on the traffic light)
Medium: 0.3–1.5 g per 100 g (amber)
Low: 0.3 g or less per 100 g (green)
Practical swaps
Choose bread with the green or amber label — supermarket own-brand wholemeal is often lower in salt than artisan loaves.
Cut back on cured meats; use roast chicken, tinned tuna in spring water or eggs instead.
Make sauces from scratch where possible. A basic tomato sauce from tinned tomatoes, garlic and herbs is far lower in salt than a jar.
Use lemon juice, vinegar, garlic, herbs, pepper and chilli to season.
What about salt substitutes?
Potassium-based salt substitutes can lower blood pressure, but they are not safe for people with reduced kidney function or those on certain blood-pressure medicines. If you have CKD, check with your GP first.
Bottom line
Most British adults could halve their salt intake just by buying lower-salt versions of the same products and cooking from scratch a couple more times a week. Your blood pressure — and your kidneys — will thank you.
Salt, blood pressure and the kidneys
UK guidance is a maximum of 6 g salt (about 2.4 g sodium) per day for adults. For people with CKD, hypertension or fluid retention, the renal target is often 5 g/day. Around 75% of UK salt intake comes from processed foods — bread, breakfast cereals, ready meals, soups, sauces and processed meats — not the salt shaker.
Blood pressure targets in CKD
NICE NG136 sets a clinic blood pressure target of below 140/90 mmHg for most adults with CKD, and below 130/80 mmHg if there is significant albuminuria (ACR ≥ 70 mg/mmol) or diabetes. Salt reduction, weight management, exercise and adherence to ACE inhibitors or ARBs do far more for kidney protection than any supplement.
Practical UK checklist for Salt, Blood Pressure and Your Kidneys: The 6 g UK Target Explained
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 "Salt, Blood Pressure and Your Kidneys" actually telling me?
How salt damages kidneys via blood pressure, where it really hides in the UK diet, and how to hit the 6 g daily target without losing flavour. The short version: read this whole page if salt, blood pressure and your kidneys is directly relevant to you, and use the TL;DR box at the top if you only have a minute.
Is salt, blood pressure and your kidneys safe for me if I have kidney disease?
Aim for under 6 g of salt a day (under 5 g if you have CKD or high blood pressure). Around three-quarters of UK salt intake hides in bread, ready meals, sauces, soups and processed meats, not the salt shaker. The detail on how this specifically applies to salt, blood pressure and your kidneys 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 salt, blood pressure and your kidneys 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
How much salt per day is safe in CKD?
Aim for under 6 g of salt (2.4 g sodium) per day; many renal teams suggest 5 g.
Are salt substitutes safe in CKD?
Most UK low-sodium salts contain potassium chloride and are not recommended in CKD.
Where is hidden salt found?
Bread, breakfast cereals, processed meats, ready meals, sauces and soups account for about 75% of UK salt intake.
Will cutting salt lower my blood pressure?
On average, halving salt intake lowers systolic blood pressure by 4–8 mmHg in adults with hypertension.
Is sea salt healthier than table salt?
No. Sea salt and Himalayan salt contain the same sodium per gram as table salt.
Kidney Vitality adds no sodium and is formulated without added potassium, magnesium, phosphorus or iron. 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). A daily multivitamin with no added sodium.
✓ 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.
