Vitamin D, cholecalciferol, is a fat-soluble vitamin. It is found in food, but also can be made in your body after exposure to ultraviolet rays from the sun. Vitamin D exists in several forms, each with a different activity. Some forms are relatively inactive in the body, and have limited ability to function as a vitamin. The liver and kidney help convert vitamin D to its active hormone form.

The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. It promotes bone mineralization in concert with a number of other vitamins, minerals, and hormones. Without vitamin D, bones can become thin, brittle, soft, or misshapen. Vitamin D prevents rickets in children and osteomalacia in adults, which are skeletal diseases that result in defects that weaken bones.

Recommended Dietary Allowances: Men = 400 IU (5 mcg); Women = 200 IU (5 mcg); Pregnant Women, Children, Adolescents = 400 IU (10 mcg)

Importance:

• Improves absorption and utilization of calcium and phosphorous required for bone and teeth formation.
• Maintains a stable nervous system and normal heart action.

Deficiency Symptoms:

• Rickets
• Tooth decay
• Softening of bones
• Improper healing of fractures
• Lack of vigor
• Muscular weakness
• Inadequate absorption of calcium
• Retention of phosphorous in the kidneys
• Osteomalacia