Annual Vitamin D Status of World-Class British Swimmers Following a Standardised Supplementation Protocol for Three Years.

British swimmers are at a heightened risk of vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D): <50 nmol∙L) as their large indoor training volumes often restrict sunlight exposure, especially during the winter when daylight hours are reduced in the United Kingdom. Previous research has recommended supplementation with 4000 IU∙day vitamin D from October to March to offset vitamin D losses. However, no current study has analysed this approach over multiple seasons to assess if this is an appropriate strategy.

Nutritional intakes of highly trained adolescent swimmers before, during, and after a national lockdown in the COVID-19 pandemic.

Strict lockdown measures were introduced in response to the COVID-19 pandemic, which caused mass disruption to adolescent swimmers' daily routines. To measure how lockdown impacted nutritional practices in this cohort, three-day photograph food diaries were analysed at three time points: before (January), during (April), and after (September) the first UK lockdown. Thirteen swimmers (aged 15 ± 1 years) from a high-performance swimming club submitted satisfactory food diaries at all time points.