The value of multiple vitamin and mineral supplementation has been examined recently in different contexts.

A systematic review and meta-analysis published in June 2018 looked at the evidence relating to the role of dietary supplements in cardiovascular disease. Supplement data included A, B1, B2, B3 (niacin), B6, B9 (folic acid), C, D and E; and β-carotene; calcium; iron; zinc; magnesium; and selenium.4,5

The researchers concluded that none of the four most commonly used supplements (multivitamins, vitamin D, calcium, and vitamin C) had a significant effect on cardiovascular outcomes €“ cardiovascular disease, stroke, or myocardial infarction. Nor did the supplements have an effect on all-cause mortality.4

Dr David Jenkins, the study's lead author, based in Toronto, said the research team was €surprised to find so few positive effects of the most common supplements that people consume.€ He added: €Our review found that if you want to use multivitamins, vitamin D, calcium or vitamin C, it does no harm €“ but there is no apparent advantage either.€5

Overall, the effects of supplementation were considered small, but folic acid alone and B vitamins with folic acid, B6, and B12 were found to reduce stroke €“ by as much as 20 per cent in the case of folic acid.4

The analysis noted a possible concern in that niacin and antioxidants, when assessed against a background in which a statin was taken, €were associated with an increased risk of all-cause mortality.€ This was by as much as 10 per cent. The researchers suggested that the finding €cautions against long-term use of extended-release (non-flush) niacin as an adjunct to statin therapy.€