Sources—Whole milk, butter, ghee, yolk, halibut-liver oil and cod-liver oil.

The rays of the sun are another cheap and potent source of Vitamin D. The skin should come in contact with the rays.

A little amount of this Vitamin is found in coconut oil, peanut oil and spinach.

There is no Vitamin D in any vegetable oil and plant food.

Lack of Vitamin D results in rickets in early childhood and abnormal tooth development and their decay in older children.

Softening of the bones (Osteomalacia)—a disease common among pregnant women—is mainly due to lack of vitamin D.

Lack of fresh air, living in a overcrowded and dark house, consumption of milk from a cow that has been kept in a dark cowshed, lack of the required quantity of calcium and phosphorous in the body (which are necessary for bone formation) contribute to the onset of the diseases caused by Vitamin D deficiency.

More Vitamin D is required when too much cereal is consumed because a toxic substance in the cereals (called toxamin) inhibits the action of this vitamin.

Extra Vitamin D is required by children to ensure proper development of their teeth and to prevent rickets.