Cytoplan GI Tract - CytoProtect

Zinc carnosine (PepZin GI)· evidence: Limited

Zinc carnosine (polaprezinc) is zinc bound to the amino acid L-carnosine. It is licensed as a medicine for stomach ulcers in Japan, and PepZin GI is the branded version sold as a supplement elsewhere.

Studies have looked at the stomach and gut lining, mostly small trials, many from Japan and many using the prescription product rather than supplements. The results are interesting but the evidence is limited, and we make no claims about any digestive condition.

As a source of zinc it works like any other zinc. If you have ongoing stomach or gut symptoms, see your GP rather than self-treating.

Typical dose: Supplements usually give 75 mg of zinc carnosine twice a day, which supplies about 16 mg of zinc in total.

Safety: Count the zinc towards the 25 mg a day the NHS advises not to exceed from supplements. Long-term zinc without copper can cause copper deficiency. Persistent indigestion, stomach pain, or blood in vomit or stools needs a GP, not a supplement.

Research we looked at:
Efthymakis K, Neri M. The role of zinc L-carnosine in the prevention and treatment of gastrointestinal mucosal disease in humans: a review. Clin Res Hepatol Gastroenterol 2022;46(7):101954.
Mahmood A, et al. Zinc carnosine, a health food supplement that stabilises small bowel integrity and stimulates gut repair processes. Gut 2007;56(2):168-175.
NHS. Others: vitamins and minerals (zinc). nhs.uk/conditions/vitamins-and-minerals/others

Vitamin A· evidence: Limited

Vitamin A (as retinol or retinyl esters, or as beta-carotene that the body converts) is needed for vision, skin and the immune system. Adults need 600 to 700 µg a day in the UK, and most people get enough from dairy, eggs, oily fish, liver and orange and green vegetables. Deficiency is rare in the UK.

There is little reason for well-fed adults to take extra vitamin A, and preformed vitamin A (retinol) builds up in the body. The NHS advises that people who eat liver weekly should not take supplements containing vitamin A, and that pregnant women should avoid them.

Beta-carotene from food is safe, but high-dose beta-carotene supplements increased lung cancer risk in smokers in large trials.

Typical dose: Adults need 600 µg (women) to 700 µg (men) a day from all sources (NRV on labels: 800 µg).

Safety: Avoid vitamin A (retinol) supplements in pregnancy or if trying to conceive; too much can harm an unborn baby. The NHS advises not having more than 1.5 mg (1,500 µg) a day from food and supplements combined, as long-term excess may weaken bones in later life. Smokers and former smokers should not take high-dose beta-carotene supplements.

Research we looked at:
NHS. Vitamin A. nhs.uk/conditions/vitamins-and-minerals/vitamin-a
EFSA NDA Panel. Scientific opinion on dietary reference values for vitamin A. EFSA Journal 2015;13(3):4028.
Omenn GS, Goodman GE, Thornquist MD, et al. Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease. N Engl J Med 1996;334(18):1150-1155.

Vitamin D3· evidence: Strong

Vitamin D3 (cholecalciferol) is the form the skin makes from sunlight. In the UK there is not enough strong sunlight from about October to March, so many people have low levels over winter. Good-quality trials show supplements reliably raise blood levels and correct deficiency, and that matters for bone health in people who are low.

The NHS advises everyone to consider 10 µg (400 IU) a day in autumn and winter, and all year round for people who get little sun, cover their skin, have darker skin or live in care homes. For people who already have adequate levels, large trials have not shown that extra vitamin D prevents falls, fractures or other illness.

In short: a modest daily dose is sensible and cheap insurance for most UK adults in winter. Very high doses are not better and should only be taken on medical advice.

Typical dose: 10 µg (400 IU) a day is the NHS advice for adults and children over 1. Doses of 25 µg (1,000 IU) to 50 µg (2,000 IU) are common and safe for adults. Babies under 1 need 8.5 to 10 µg a day unless they have more than 500 ml of formula.

Safety: Do not take more than 100 µg (4,000 IU) a day without medical advice (FSA/NHS); children aged 1 to 10 should not have more than 50 µg, and babies under 1 no more than 25 µg. Long-term very high intake can raise blood calcium, which can damage the kidneys and heart. People with kidney disease, sarcoidosis or high calcium levels should speak to their GP first.

Research we looked at:
NHS. Vitamin D. nhs.uk/conditions/vitamins-and-minerals/vitamin-d
Scientific Advisory Committee on Nutrition (SACN). Vitamin D and Health. 2016.
EFSA NDA Panel. Scientific opinion on the tolerable upper intake level for vitamin D. EFSA Journal 2023;21(8):8145.
Bolland MJ, Grey A, Avenell A. Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis. Lancet Diabetes Endocrinol 2018;6(11):847-858.

Spore-forming cultures (Bacillus)· evidence: Insufficient

Bacillus coagulans (now also called Heyndrickxia or Weizmannia coagulans, sold as LactoSpore and other brands) and Bacillus subtilis form hard spores. That makes them stable in gummies, powders and capsules without refrigeration, which is their main practical advantage.

Human studies on these strains are few, mostly small and often funded by ingredient makers, with mixed results. There are no authorised health claims, so we make no claims about what they do.

Typical dose: Products typically provide 1 to 3 billion spores a day.

Safety: Generally well tolerated. Speak to your doctor first if you have a weakened immune system or are seriously ill.

Research we looked at:
Cutting SM (2011). Bacillus probiotics. Food Microbiology 28(2):214-220.
NCCIH. Probiotics: what you need to know. National Institutes of Health.

Cost per daily dose lets you compare packs of different sizes fairly.Worked out from our current prices.