Maughan et al. 2018, IOC consensus on dietary supplements

IOC consensus statement (British Journal of Sports Medicine 2018) on dietary supplements for the high-performance athlete. The core position is food-first: nutrition makes a small but valuable contribution to performance and most supplements add little or nothing over a good diet, so a complete nutritional assessment should precede any supplement use. Of the many performance supplements marketed, only a few have good evidence of benefit — caffeine, creatine, nitrate, sodium bicarbonate and possibly beta-alanine. Micronutrient supplements (notably iron, calcium and vitamin D) are warranted only to correct a diagnosed deficiency, and high-dose iron should not be taken unless deficiency is present. The statement also stresses the risk of inadvertent anti-doping violations from contaminated or mislabelled products and advises choosing independently batch-tested supplements. Strong (expert consensus).