Athletes need to train, no matter what: rain or shine, early mornings, late evenings, sore muscles, or low energy. Vitamin D may help to improve the quality, frequency and duration of training, and contribute to faster muscle recovery. Klean-D 5,000 IU contains natural vitamin D₃, providing targeted support for athletes who train indoors or receive limited exposure to natural sunlight. Vitamin D supplementation may also help support athletes' immune health, musculoskeletal strength and physical performance.^‡