What Does Chromium Do for Blood Sugar? The Claim, the Trials, the Dose

Chromium is a trace mineral, and the one blood-sugar ingredient with an authorised health claim in Great Britain: "Chromium contributes to the maintenance of normal blood glucose levels" and "Chromium contributes to normal macronutrient metabolism", for any food or supplement supplying at least 15% of the 40 µg daily reference intake.^{1, 13} In people with type 2 diabetes, a 2020 pooling of 28 trials found HbA1c about 0.7 percentage points lower, with very wide variation between trials; in people without diabetes, a 2002 pooling of 15 trials found no relationship between chromium and glucose or insulin.^{2, 3} For weight, the Cochrane review found body weight 1.1 kg lower on chromium picolinate than on placebo over 12 to 16 weeks, and rated the evidence low quality.⁴

Sources checked on 30 October 2026.

• The claim: 6 µg or more per daily serving; it belongs to the mineral, not to berberine or vinegar
• The trials: a 0.7-point HbA1c change in type 2 diabetes at supplement doses; nothing measurable in people without diabetes
• The cancer question: industrial hexavalent chromium, breathed in; food and supplement chromium is trivalent

What does chromium do in the body?

Trivalent chromium is thought to help insulin do its job: once insulin binds to a cell, a small chromium-binding molecule appears to sharpen the signal that tells the cell to take up glucose.⁵ That is the biology behind both authorised wordings, and it is contested. The European Food Safety Authority reviewed chromium in 2014 and set no dietary reference value, finding no evidence that healthy people benefit from any particular intake, and a 2017 review argued that at supplement doses chromium behaves more like a drug than a nutrient.^{5, 6} The NHS gives a working figure of about 25 µg a day and says a varied diet supplies it.⁷

What does the UK claims register allow for chromium?

Two sentences, verbatim: "Chromium contributes to normal macronutrient metabolism" and "Chromium contributes to the maintenance of normal blood glucose levels".¹³ The condition: at least 6 µg of trivalent chromium, 15% of the 40 µg reference intake, per daily portion. Chromium is often added to berberine capsules and to apple cider vinegar and ginger gummies at a level above that threshold so that the pack can carry the wording. In each case the blood-glucose wording belongs to the chromium, not to the berberine, vinegar or ginger, none of which has an authorised claim; the Wellgard berberine guide sets out berberine's trials in UK units.

Does chromium lower blood sugar? What the trials found

In type 2 diabetes, yes on average, at supplement doses. The 2020 meta-analysis of 28 randomised trials found fasting glucose about 19 mg/dL lower, roughly 1 mmol/L, HbA1c 0.71 percentage points lower and insulin resistance improved, with very wide variation between trials.³ In people without diabetes, no: the 2002 meta-analysis of 15 trials, 618 people of whom 425 did not have diabetes, found no relationship between chromium and glucose or insulin in those without diabetes, and called the diabetes data inconclusive.² So "is chromium good for diabetics?" has a numeric answer: a 0.7-point HbA1c change at trial doses, always alongside prescribed treatment and never instead of it.

Does chromium help with weight or belly fat?

The Cochrane review pooled six trials of 392 overweight or obese adults taking chromium picolinate at 200 to 1,000 µg a day for 12 to 16 weeks and found body weight 1.1 kg lower than placebo (0.4 to 1.7 kg), with no sign that higher doses did more; the authors graded the evidence low quality and called the difference "of debatable clinical relevance".⁴ No trial has measured belly fat specifically.

Is it safe to take chromium picolinate every day?

At UK supplement amounts, yes for most adults. The NHS says 10 mg (10,000 µg) or less a day from food and supplements combined is unlikely to cause harm, and EFSA has set no upper limit for trivalent chromium.^{6, 7} The caution sits at the top of the market: the Cochrane review recorded two serious adverse events in the 1,000 µg groups, and there is a published case of kidney failure attributed to over-the-counter chromium picolinate.^{4, 8} "Which chromium is best?": the register wording covers trivalent chromium in any form, and the weight trials used picolinate.^{4, 13}

Who should avoid chromium?

Three groups should ask before any chromium supplement, including the small amounts in multi-ingredient products. People on glucose-lowering medicines, including insulin, gliclazide, glimepiride and metformin, because anything that affects glucose adds to what the medicine does and the diabetes team should know. People with kidney disease, because of the published kidney case above. And people who are pregnant or breastfeeding, who should check with a midwife. One more: in a small study, chromium picolinate swallowed at the same time reduced levothyroxine absorption, so take it hours apart from thyroid medicine as you would iron or calcium.⁹

What cancers does chromium cause?

None linked to the chromium in food or supplements. The cancer record belongs to hexavalent chromium, chromium(VI), an industrial form that the UK Health Security Agency classes as carcinogenic to humans by the inhalation route; the same overview lists chromium(III) compounds as not classifiable as to carcinogenicity.¹⁰ The chromium in food and supplements is trivalent, a different oxidation state with a different toxicology.

What foods are high in chromium?

Meat, nuts and cereal grains, according to the NHS, which says a varied and balanced diet supplies all the chromium you need.⁷

What are the signs of chromium deficiency?

There is no validated list, because chromium deficiency from food has never been demonstrated. The clear human cases are people fed intravenously for years with no chromium in the feed: the 1977 report describes a woman whose glucose intolerance, weight loss and nerve symptoms resolved after chromium was added to her feed, a deficiency case that does not apply to food or supplements.¹¹ Tiredness, cravings or blood-sugar swings are not signs of chromium deficiency, and symptoms like those need a GP and an HbA1c, not a mineral.

Blood sugar supplements: what the UK register allows

Very little. Chromium carries the two wordings above. A short list of fibres, beta-glucans from oats and barley, arabinoxylan, pectins, hydroxypropyl methylcellulose, alpha-cyclodextrin and resistant starch, may say they contribute to a smaller rise in blood glucose after a meal, when eaten as part of it.¹³ Zinc may say it contributes to normal carbohydrate metabolism (what is zinc good for lists its other wordings). Berberine has no claim; cinnamon's is on hold as a botanical; bitter melon, alpha-lipoic acid and chlorogenic acid were assessed and rejected, so "which spices lower sugar levels?" has the same answer: none with an authorised claim. For anyone with diabetes, the NHS pages on diet and activity are the place to start, and any supplement with a glucose effect is something to tell the diabetes team about.¹²

What we don't know

Whether the few micrograms of chromium in a multi-ingredient supplement do anything measurable has not been tested; the weight trials used 200 to 1,000 µg.⁴ In people without diabetes the pooled trials show no glucose effect and EFSA found no evidence of benefit from any intake.^{2, 6} The type 2 diabetes result varies enormously between trials, and no trial has compared one form of chromium with another.³

Frequently asked questions

Is it okay to take chromium picolinate daily?

At label doses, yes for most adults: the NHS puts the level unlikely to cause harm at 10 mg a day, far above any UK supplement.⁷ Tell your diabetes team if you take glucose-lowering medicines, and avoid high-dose products if you have kidney disease.

Can I take chromium with metformin?

There is no study of the two together. The issue is additive glucose lowering rather than a chemical interaction, so tell the diabetes team and watch your meter for a fortnight. Never adjust metformin yourself.

Does B12 speed up metabolism?

No. The authorised wording is that vitamin B12 contributes to normal energy-yielding metabolism, which describes its role in the chemistry that releases energy from food, not a faster metabolic rate or weight change.¹³

What supplements should people with diabetes stay away from?

Anything taken without telling the diabetes team, especially products with a glucose-lowering effect, because the combined effect with insulin or gliclazide can be a hypo. Berberine, chromium above the reference intake and vinegar all belong in that conversation.

What is a good natural supplement for diabetes?

No supplement is a treatment for diabetes and no herb has an authorised blood-glucose claim in Great Britain; chromium's wording is about normal glucose levels, not disease.¹³

Sources

1. EFSA NDA Panel. Scientific Opinion on health claims related to chromium: macronutrient metabolism and maintenance of normal blood glucose concentrations. EFSA Journal, 2010. Scientific opinion behind the authorised wordings. doi.org/10.2903/j.efsa.2010.1732.
2. Althuis MD, et al. Glucose and insulin responses to dietary chromium supplements. American Journal of Clinical Nutrition, 2002. Meta-analysis, 15 randomised trials, 618 people, 425 without diabetes; funding not stated on PubMed. PubMed 12081828.
3. Asbaghi O, et al. Effects of chromium supplementation on glycemic control in patients with type 2 diabetes. Pharmacological Research, 2020. Meta-analysis, 28 randomised trials in type 2 diabetes; funding not stated on PubMed. PubMed 32730903.
4. Tian H, et al. Chromium picolinate supplementation for overweight or obese adults. Cochrane Database of Systematic Reviews, 2013. Cochrane review, 9 randomised trials, 622 adults, weight pooled from 6 trials and 392 adults; no conflicts declared. PubMed 24293292.
5. Vincent JB. New evidence against chromium as an essential trace element. Journal of Nutrition, 2017. Narrative review; author holds chromium-supplement patents. PubMed 29021369.
6. EFSA NDA Panel. Scientific Opinion on Dietary Reference Values for chromium. EFSA Journal, 2014. Scientific opinion; no reference value set. doi.org/10.2903/j.efsa.2014.3845.
7. NHS. Others: vitamins and minerals (chromium). nhs.uk. Page last reviewed 3 August 2020 (review overdue). Read 30 October 2026.
8. Wasser WG, et al. Chronic renal failure after ingestion of over-the-counter chromium picolinate. Annals of Internal Medicine, 1997. Case report. PubMed 9054292.
9. John-Kalarickal J, et al. New medications which decrease levothyroxine absorption. Thyroid, 2007. Crossover study, 7 healthy volunteers; funding not stated on PubMed. PubMed 17725434.
10. UK Health Security Agency. Chromium: toxicological overview. gov.uk. Read 30 October 2026.
11. Jeejeebhoy KN, et al. Chromium deficiency, glucose intolerance, and neuropathy reversed by chromium supplementation, in a patient receiving long-term total parenteral nutrition. American Journal of Clinical Nutrition, 1977. Case report, one woman on long-term intravenous feeding. doi.org/10.1093/ajcn/30.4.531; PubMed 192066.
12. NHS. Type 2 diabetes: food and keeping active. nhs.uk. Page last reviewed 10 February 2025. Read 30 October 2026.
13. Great Britain nutrition and health claims (NHC) register: chromium, zinc, vitamin B12 and post-meal glucose wordings and their conditions. gov.uk. Page last updated 19 May 2026. Read 30 October 2026.

Spotted something out of date? Email support@wellgard.co.uk with the page address and the sentence.

This article is general information, not medical advice. If you have diabetes, take insulin or glucose-lowering tablets, have kidney disease, or are pregnant or breastfeeding, ask your diabetes team, pharmacist or midwife before taking a chromium supplement, and never change a prescribed medicine on the strength of a supplement.