Vitamin-d

Women's supplement needs change substantially across reproductive life stages. This article reviews evidence-based supplement priorities for women of reproductive age, during pregnancy, postmenopause, and in specific clinical circumstances.

Most dietary supplements are not necessary for healthy adults eating varied diets. A small number address genuinely common deficiencies or have strong clinical evidence for specific populations. This article identifies the supplements most likely to provide real benefit and why.

Food supplements serve specific, evidence-defined purposes — correcting nutritional deficiencies, meeting elevated needs in particular life stages, and providing therapeutic doses of specific nutrients. This article explains what each major supplement category is for, with the evidence and UK regulatory context.

Dietary supplements are beneficial in specific, defined contexts: correcting deficiencies (vitamin D, B12, folate, iron), supporting life stages with increased needs (pregnancy, older adults), and supplementing macronutrients when food intake is insufficient. This article covers where supplements have genuine evidence and where claims exceed the evidence.

Vitamin supplementation is not universally necessary for people eating a varied diet. UK-specific evidence-based indications: vitamin D (10 mcg/day for all UK adults — SACN 2016), folic acid (400 mcg/day before and during early pregnancy — NICE), vitamin B12 (vegans and strict vegetarians), iron (only if deficiency confirmed by blood test). A SACN review concluded there is no consistent evidence that multivitamins benefit well-nourished UK adults.