Footballers get a vitamin d boost: High-Dose supplement and exercise combo shows big changes

This study looked at how a single high dose of vitamin D (500,000 IU) combined with a football match affects vitamin D levels in 20 professional male football players. Half got the vitamin D, half got a placebo. Blood tests before and after the game showed that the supplement greatly increased vitamin D in the blood, and exercise also helped raise levels. The study was small and only measured short-term changes, so it doesn't prove any health benefits or long-term effects.