Summer is the season when many women focus on wellness, hydration, and spending more time outdoors. But health experts say one common vitamin D supplement mistake could be putting some women at risk of nutrient deficiencies or, in some cases, unnecessary over-supplementation. As sunshine-filled days arrive, many people assume they no longer need a vitamin D supplement because they are spending more time outside. However, doctors warn that the relationship between sunlight and vitamin D levels is far more complicated than many realize. Understanding the facts can help women make safer decisions about their health this summer.