Vitamin & Mineral Supplement Dose Calculator
Calculate the recommended daily intake and safe upper limits for vitamins and minerals based on NHS and EFSA guidelines. Know what to supplement and how much.
Vitamin and Mineral Supplementation Guide
UK Vitamin D Guidance
NHS recommendation: all UK adults and children over 1 year should consider taking 10 micrograms (400 IU) of vitamin D daily from October to March. People at higher risk (dark skin, little sunlight exposure, housebound) should supplement year-round. Evidence-based safe supplementation: 1,000-2,000 IU (25-50 mcg) daily is widely considered safe and more likely to achieve adequate blood levels than the minimum NHS recommendation. Upper safe limit: 4,000 IU (100 mcg) daily for adults. Above 10,000 I
Vitamin B12 for Vegans
Vitamin B12 is found almost exclusively in animal products. All vegans should supplement B12 reliably — B12 deficiency develops slowly (body stores last 2-5 years) but causes irreversible neurological damage if untreated. NHS recommendation for vegans: 2,000 mcg cyanocobalamin weekly OR 50 mcg daily. Alternative: nutritional yeast fortified with B12 and fortified plant milks (check label — not all brands add B12). Methylcobalamin vs cyanocobalamin: both effective for most people. Cyanocobalamin
Iron Supplementation
Iron deficiency anaemia: the most common nutritional deficiency worldwide. Women of reproductive age, vegetarians/vegans, and frequent blood donors are at highest risk. NHS recommended dose for treating deficiency: ferrous sulfate 200mg (65mg elemental iron) once to three times daily. For maintenance/prevention: 14mg elemental iron daily (adult RNI). Types of iron: ferrous sulfate — cheapest, effective but may cause GI upset. Ferrous gluconate/fumarate — gentler on stomach, slightly less iron pe
Omega-3 Evidence
Omega-3 fatty acids EPA and DHA are found mainly in oily fish. NHS recommendation: eat 2 portions of fish per week, one of which is oily (salmon, mackerel, sardines, trout). Supplement recommendation: 250-500mg EPA+DHA daily for cardiovascular health. For people who eat no fish: consider a supplement. Evidence: strong evidence that omega-3 reduces triglycerides and modestly reduces cardiovascular risk. Less strong evidence for other claimed benefits (cognitive function, mood, inflammation). Vega
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