4. Vitamin D Deficiency
Vitamin D is critical to bone health because it helps the body to absorb calcium. New research has also pointed to the importance of vitamin D for preventing cardiovascular disease, cancer, and cognitive impairment. If you have a deficiency, you might experience bone pain or muscle weakness, but these symptoms are often mild.
Vitamin D synthesizes in the body when your skin is exposed to sun, so many people experience a deficiency during winter months or if they live in northern latitudes. Food sources of vitamin D are mostly animal based, including egg yolks, fish and fish oils, fortified milk, and beef liver. If you are a strict vegan, the risk of vitamin D deficiency is higher.