A new Which? investigation has exposed dangerously high doses of vitamins and minerals being sold on major online marketplaces. AliExpress, Amazon, eBay, Superdrug, Temu, and TikTok Shop were all scrutinised, revealing some supplements pack doses well beyond NHS safe limits.
Vitamin D Overdoses Lurking Online
The NHS recommends adults take just 10 micrograms (µg) of Vitamin D daily — and no more than 100µg safely. Yet, Superdrug Marketplace, TikTok Shop, and eBay were found selling Vitamin D3 at a staggering 10,000 IU (250µg). This is 25 times the daily recommended intake! Nuke Nutrition swiftly pulled their 10,000 IU supplement after concerns were raised.
Even worse, AliExpress listed Vitamin D3 capsules in a whopping 50,000 IU (1,250µg) dose — that’s 12.5 times the safe upper limit. According to the NHS, such mega doses risk hypercalcaemia (too much calcium in the blood), which can cause vomiting, bone weakness, confusion, and potentially kidney failure.
Supplements for Kids Over the Limit
Children’s Vitamin D supplements were also found with excessive doses. Temu sold “Growth” and “Height Growth Maximiser” supplements labelled for kids containing 2,500 IU (62.5µg) — above the recommended 2,000 IU limit for under-10s.
Vitamin A, B6, and Zinc Doses Raise Alerts
- Vitamin A: NHS advises max 1,500µg daily (EFSA suggests 3,000µg). Yet Etsy, TikTok, and eBay sold a 7,500µg dose from Mother Nature — 2.5 times EU limits.
- Vitamin B6: Recommended max is 10mg, but supplements found on Temu, Solgar, and Holland & Barrett contained 100mg — ten times the safe level. Holland & Barrett withdrew these after being contacted.
- Zinc: NHS caps intake at 25mg, but the popular WeightWorld zinc on Amazon had 50mg, and eBay/TikTok sold Now Foods zinc at the same dose, even labelled “Amazon’s Choice”. Superdrug also offered 50mg from New Leaf.
The NHS warns high zinc can cause copper deficiency, leading to anaemia and fatigue.
Which? Demands Tighter Controls
“It’s shocking that supplements containing potentially dangerous doses of popular vitamins and minerals are so readily available online,”
Sue Davies, Head of Food Policy at Which? said. “Excess doses can cause serious harm, like liver damage and brittle bones. We urgently need stricter regulation, so consumers aren’t left at risk from these dangerously strong supplements.”
Responses from Retailers: Damage Control Underway
- AliExpress: Claimed the offending products were removed before Which?’s enquiry.
- Amazon: Insists all products meet current government rules but acknowledged ongoing debate on safe limits.
- eBay: Said NHS and Food Standards guidelines are advisory, and policies are under review.
- Holland & Barrett: Pulled high-dose B6 products, reformulating to meet EFSA advice by October 2025.
- Mother Nature: Added warnings recommending doctor consultation before high-dose use.
- New Leaf: Defended 50mg zinc as flexible dosing for targeting colds and skin health.
- Superdrug: Removed all highlighted products from their marketplace.
- Temu & TikTok Shop: Confirmed removal of flagged listings and compliance with UK laws.
Stay Safe: Know Your Limits
Experts remind shoppers to stick to NHS-approved vitamin and mineral doses. Overdoing it isn’t just a waste of money — it could seriously harm your health.
For full details on safe supplement practices, keep an eye on Which? and NHS updates — and as always, consult your doctor before starting any high-strength vitamins.
