Vitamin D: Vitamin D is a fat-soluble nutrient that is naturally present in very few foods and added to others. It is produced endogenously when UV-rays from sunlight strike the skin and trigger vitamin D synthesis. It must go two hydroxylations in the body for activation.
It is sometimes referred to as “sunshine vitamins”. It is not strictly a vitamin but considered us hormone as its synthesis occurs in a different location.
Recommended Daily Allowance of Vitamin D
- 0 – 12 months -> 400 IU (10 mcg)
- 1 – 13 years -> 600 IU (15 mcg)
- 14 – 70 years -> 600 IU (15 mcg)
- More than 70 years -> 800 IU (20 mcg)
Sources of Vitamin D
- Cod liver oil, swordfish, salmon, Tura, Milk, yogurt, Liver, Beef, Egg, Cereal, cheese, Orange juice.
- Sun exposure: Ultraviolet radiation with wavelength 290 – 320 nanometers penetrates the uncovered skin.
- Supplement: Fortified food with 10 DIU/100 ml supplies vitamin D through the supplement.
Importance of Vitamin D
- Promotes calcium absorption in the gut.
- Maintains adequate scrum calcium and phosphate concentration to enable normal mineralization of bone.
- Prevent hypocalcemic tetany.
- prevents thin, brittle, mishappen bones.
- In older adults, prevents osteoporosis.
- Prevent osteomalacia.
- Increase absorption of calcium, iron, zinc, magnesium, phosphate in the intestine.
Deficiency Risks of Vitamin D
- Rickets – soft, weak, deformed, lorry bones called bow legs.
- Thin and brittle bones.
- Reduce bone mineral density.
- Skin pigmentation.
Toxicity: (more than 1250 µg) of Vitamin D
- Renal failure.
- Metastatic calcification.
- Urinary cast.