You’re prone to stress fractures
“Most people think of a lack of calcium when talking about bone health, which is true. However, without vitamin D, calcium doesn’t get absorbed properly,” says Jennifer Giamo, a nutritionist, certified personal trainer, and founder of New York City-based Trainers in Transit. “Vitamin D, specifically D3, which increases calcium absorption, is critical to preventing bones from becoming thin and brittle.” A study in The Journal of Foot and Ankle Surgery found that people who participate in higher-impact activities may need greater levels of vitamin D to reduce their risk of stress fractures. In addition to the vitamin D deficiency symptoms that can put you at risk, make sure you know these signs of a calcium deficiency.