The importance of Vitamin D for kids

Vitamin D is a nutrient that helps the body use calcium and phosphorous to build and maintain strong bones and teeth. Too little vitamin D can cause calcium and phosphorus levels in the blood to decrease, leading to calcium being pulled out of the bones to help maintain stable blood levels. This can cause rickets in children and osteomalacia (softening of the bones) or osteoporosis (fragile bones) in adults. However, too much vitamin D can cause too much calcium to be deposited in the body, which can lead to calcification of the kidney and other soft tissues including the heart, lungs and blood vessels.

Children were once at great risk of rickets, a bone disease that could cause bowing of a child's legs, swelling of their wrists and ankles, and failure to thrive or poor weight gain. With the introduction of vitamin D supplementation of infant formula and milk, rickets was soon considered a rare disease. In addition to supplements, children can receive vitamin D from exposure to sunlight, which stimulates vitamin D production in the skin. Because dark skinned children and those that aren't exposed to enough sunlight have always been thought to be at risk of rickets, it has long been recommended that they receive vitamin D supplements if they weren't drinking baby formula (infants) or vitamin D fortified milk (older children), but it wasn't thought that most other kids needed extra vitamin D