Vitamin D is most commonly obtained by sunlight exposure. Some foods like fish, egg yolk, fortified dairy products also contain this vitamin. Vitamin D is needed to make the bones healthy and strong. The vitamin helps in using calcium from the food we eat. Children can have asthma due to Vitamin D deficiency. The deficiency can cause rickets, in which the bones become very soft and it leads to bone deformities. If you do not take enough Vitamin D, you can have pain in the bones. Your muscles can become weak. The elderly people can have cognitive impairment. The 10 health dangers of Vitamin D deficiency are as follows.