Experts have issued a warning that certain multivitamin brands might be inadvertently misleading consumers about their actual Vitamin D intake. An investigation by the Daily Mail revealed that numerous supplements sold in Britain contain significantly less Vitamin D than recommended for adults, despite some packaging claiming to provide '100 per cent' of daily requirements.

The core of the issue stems from an outdated regulatory framework. While the NHS advises adults and children over four years old to consider taking a daily 10 microgram (mcg or µg) Vitamin D supplement during the autumn and winter months due to limited sunlight exposure, supplement labels are still based on a European nutrient reference value (NRV) of 5mcg. This NRV, established decades ago, is only half of the current UK recommended intake. Consequently, products containing just 5mcg can legally be marketed as providing '100 per cent' of daily Vitamin D, even though they only supply 50 per cent of what the UK government currently advises.

Dr Carrie Ruxton, a dietitian from the Health & Food Supplements Information Service (HSIS), highlighted the confusion this discrepancy causes consumers. She explained, "We've got this really strange anomaly in labelling law where the NRV comes from older European regulations and doesn't match current UK recommendations. People may discover they are low in vitamin D, buy a supplement and see that it contains 100 per cent of their intake and assume that's enough. In reality, 5mcg is only half of what the UK Government recommends. The NRV for Vitamin D is out of date and needs to double."

Vitamin D, often referred to as the 'sunshine vitamin,' is naturally synthesized in the skin when exposed to sunlight and can also be obtained from foods like oily fish, eggs, and fortified cereals. It plays a crucial role in regulating calcium and phosphate levels, which are essential for maintaining healthy bones, teeth, and muscles.

The Daily Mail's review of popular multivitamin brands available in high street pharmacies confirmed that most labels continue to adhere to the older 5mcg NRV system. Many of the products with the lowest doses are gummy supplements, and the variation in recommended serving sizes (e.g., number of capsules or gummies) further complicates matters for shoppers trying to ascertain their actual intake.

For instance, Nutriburst Health and Vitality Vitamin Gummies provide only 1.5mcg of Vitamin D per two-gummy serving, which is equivalent to just 15 per cent of the UK recommendation. Their nutritional information on the Boots website states this as 30 per cent of the NRV. Similarly, Boots Multivitamin Gummies offer 5mcg per serving, while two products from Health & Her contain 2.5mcg per serving. The packaging for Boots Multivitamin Gummies explicitly states 5mcg of Vitamin D3 per gummy, claiming '100 per cent' of the NRV. The Health & Her products' labels indicate that two tablets "typically provide" 2.5mcg of Vitamin D3, or 50 per cent of the NRV.

Even among products with higher amounts, serving sizes often vary, requiring consumers to meticulously check instructions to understand their true dosage. A detailed list of adult multivitamins with low Vitamin D content revealed many brands providing 5µg (micrograms) of Vitamin D per serving, which equates to 100% of the EU NRV but only 50% of the NHS guidance. These included Boots A–Z Multivitamin + Live Friendly Bacteria, Boots A–Z + Ginseng, Boots Multivitamins with Iron, Boots Everyday Multivitamins, Boots Multivitamin Gummies, Boots Multivitamins Orange Flavour, Centrum Women Multivitamins & Minerals, Centrum Men Multivitamins & Minerals, Bassetts Multivitamins Raspberry & Pomegranate Flavour Soft & Chewies, Gold Collagen Forte, Chewy Vites Adults Multivitamin Complete, Seven Seas Cod Liver Oil Plus Multivitamins Omega–3 Fish Oil, and Bettervits Multivitamin Capsules.

On the opposite end, the Daily Mail's analysis identified one multivitamin offering 45mcg of Vitamin D per serving, which is significantly above the daily guidance but still within the UK's safe upper limit. It's also worth noting that some supplements utilize Vitamin D2 (ergocalciferol) instead of Vitamin D3 (cholecalciferol), with the latter generally considered more effective in elevating blood Vitamin D levels.

While excessive Vitamin D intake can, in rare instances, lead to toxicity—manifesting as high calcium levels, kidney issues, nausea, weakness, and confusion—this is typically associated with very high-dose supplements rather than dietary intake or sun exposure.

Food supplements sold in England are regulated under the Food Supplements (England) Regulations 2003, distinguishing them from medicines. These regulations mandate clear labeling as 'food supplements' and require key information such as ingredients, recommended daily intake, and the manufacturer's details. Safety warnings are also compulsory, advising consumers not to exceed the recommended daily dose, to keep products out of reach of children, and emphasizing that supplements should not substitute a varied, balanced diet. Furthermore, labels must clearly state the amount of any vitamins, minerals, or other substances with nutritional or physiological effects.

Strict limits are imposed on health claims; supplements cannot be marketed as preventing, treating, or curing diseases, and any authorized health claims must comply with the UK Nutrition and Health Claims Regulation. Unlike medicines, there isn't a single, fixed set of legal maximum levels for all vitamins and minerals in supplements across the UK. Instead, safety is determined through scientific guidance, enabling regulators to act if a product presents a risk. Following Brexit, these regulations were integrated into UK domestic law, with national authorities now responsible for their enforcement.

In response to the investigation, several brands provided statements:

Tarun Kapoor, Chief Operating Officer of Nutriburst, stated that their Health & Vitality Multivitamin Gummies do not claim to provide a full daily dose of Vitamin D, with the amount and its NRV percentage clearly displayed. He noted that the product was formulated as a balanced multivitamin rather than to deliver 100 per cent of any single nutrient. This specific product is being discontinued and will be replaced with new Men's and Women's formulations featuring higher Vitamin D levels (10 µg per serving) and an optimized nutrient profile, demonstrating a commitment to clear labeling and continuous improvement.

Dr Robin Andrews from Health & Her explained that their multivitamins for women using hormonal contraception or hormone replacement therapy (HRT) were developed based on evidence showing how exogenous hormones influence nutrient metabolism. Given that women on oral contraceptives or HRT often exhibit higher circulating 25–hydroxyvitamin D levels, a conservative approach to Vitamin D inclusion was adopted to prevent exceeding recommended thresholds.

Mondelez International (Bassetts) confirmed that their Multivitamins comply with all regulatory requirements and that they are in the process of increasing Vitamin D across their adult range, having already raised it to 10 µg per serving in children's vitamins. For consumers specifically seeking Vitamin D, Bassetts offers products with 25 µg, 15 µg, and 10 µg per serving, depending on the range.

A spokesperson for Bettervits clarified that the role of a multivitamin dietary supplement is to complement, rather than replace, a balanced diet. The expectation is to provide a broad spectrum of nutrients to address dietary deficiencies, not to supply 100 per cent of each nutrient as a substitute for food. However, Bettervits also offers a potent strength Vitamin D Complex containing 100µg (4,000 IU), combined with synergistic Vitamin K2 MK-7, marketed as a super strength supplement particularly beneficial during the UK's winter months.

Boots, Centrum, and Seven Seas were also contacted for comment regarding the findings.