Question: what micronutrient deficiencies can be common in athletes?
Answer: Vitamin D. Athletes can become deficient in vitamin D because they wear too much sunscreen or clothing that blocks the sun, making them unable to convert vitamin D from sunlight to an active form in their body, or because they don't eat foods with vitamin D, such as milk or eggs. ... 
Calcium. ... 
Iron. ... 
Potassium. ... 
Fiber.