The sceptic’s line is that supplements just make “expensive urine.” It’s a good soundbite, and for water-soluble vitamins taken in excess there’s a grain of truth — the surplus is excreted. But it misses the point, because the argument only holds if you’re replete in the first place, and UK population data show many people are not:
• low vitamin D status affects roughly one in five adults across the year and around a third in winter; 1.
• 83% of women of childbearing age fall below the target red-cell folate level; 2.
• low iron is common in menstruating women, and B12 is frequently low in older adults, vegans, and long-term metformin or PPI users.
A sensibly dosed multivitamin isn’t about buying insurance against a perfect diet — it’s about closing the specific, evidence-based gaps that are genuinely common in the UK. Food first; then fill the real gaps.
1. National Diet and Nutrition Survey, rolling programme 2019–2023. Office for Health Improvement & Disparities / Food Standards Agency (2025) — vitamin D and folate status data.
2. National Diet and Nutrition Survey 2019–2023 — red-blood-cell folate below the neural-tube-defect risk threshold in 83% of women aged 16–49.
