Vitamin D deficiency can be caused by:

• inadequate intake with inadequate sunlight exposure
• liver and kidney disorders
• hereditary disorders
• fat malabsorption

The deficiency leads to:

• bone mineralization
• bone softening
• rickets in children
• osteomalacia
• osteoporosis

Vitamin D malnutrition may also cause following chronic diseases:

Adequate Intake (AI) of Vitamin D:

• Children 0-13 years 5 mg per day (200 IU)
• Adolescents 14-18 years 5 mg per day (200 IU)
• Adults 19-50 years 5 mg per day (200 IU)
• Mature 50-70 years 10 mg per day (400 IU)
• 71+ years 15 mg per day (600 IU)

Following foods are rich in Vitamin D:

• Fish liver oils
• Fatty fish (catfish, salmon, mackerel, sardines, tuna, eel)
• Mushrooms
• Eggs
• Milk
• Cheese

However, sun exposure is most important source of vitamin D. Most human receives their vitamin D requirement by exposure to sunlight.

Vitamin D is fat-soluble and stored in body as calcidiol. However Vitamin D toxicity appears only if excessive doses are taken.
Sunlight does not cause Vitamin D toxicity.

Vitamin D toxicity can cause:

• nausea
• vomiting
• poor appetite
• constipation
• weakness
• weight loss
• raise blood levels of calcium (causing confusion, heart rhythm abnormalities)

Vitamin D is a group of fat-soluble prohormones. Most active forms of vitamin D are ergocalciferol (also known as vitamin D2 ) and Calciferol (Vitamin D3). Skin produces vitamin d3 after exposure to ultraviolet rays.

The major function of Vitamin D is keeping blood levels of calcium phosphorus. Vitamin D play role in formation and maintaining strong bones. Vitamin D also helps to maintain healthy immune system and plays role in immunomodulation.

Vitamin D was discovered In 1922 by Edward Mellanbywhile researching a rickets disease.