Iodine

UK evidence-based supplements for vegetarians: B12 is essential for vegans and recommended for low-dairy vegetarians (SACN); vitamin D 10 mcg/day for all UK adults regardless of diet (SACN 2016); iodine 150 mcg/day for those limiting dairy (SACN 2014); omega-3 as algal oil (EPA+DHA) if not eating oily fish. Iron: test first — do not supplement without confirmed deficiency. Lacto-ovo vegetarians eating dairy and eggs regularly have fewer critical gaps.

Several nutrients have strong evidence for brain development: DHA (EFSA authorises 100 mg/day claim for infant brain development), iodine (SACN 2014: deficiency associated with cognitive impairment in children; UK vegetarians/vegans at risk), iron (deficiency in early life causes irreversible cognitive deficits — NICE recommends testing before supplementing), choline (UK has no RNI; most diets adequate). Folic acid prevents neural tube defects (NICE: 400 mcg/day in first trimester). B12: critical for myelin development in vegan/vegetarian infants.

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