Vitamin D is absorbed by our bodies naturally through sunlight. Individuals who are deficient in Vitamin D can develop a condition known as osteomalacia, where their bones begin to soften. People with digestive problems, celiac disease, liver problems or Crohn’s disease are also more likely to have low levels of the vitamin. Vitamin D is crucial to the building and maintenance of healthy bones and teeth. Vitamin D has also been found to assist with controlling sleep patterns and combatting seasonal depression.