VITAMIN D

VITAMIN D

    Vitamin D is otherwise known as ‘sunshine vitamin’ as it can be synthesized from sunlight by our body.
       
    Functions
    1. Vitamin D promotes the absorption of calcium and phosphorus from the small intestine
    2. In the DNA vitamin D helps to form active calcium binding protein
    3. It also maintains the concentration of calcium and phosphorus in the blood
    4. Vitamin D helps the deposition of calcium phosphate in the bone. In rachitic children there may be delay in dentition and malformation of the teeth occurs
       
    Deficiency
    • Deficiency of vitamin D results in poor absorption of calcium and phosphorus from the intestine and excessive loss of them in the urine and faeces.
    • Concentration of calcium in the plasma is diminished and it produces tetany which is characterized by hyperexcitability of the nervous system.
    • This stimulates the parathyroid glands to decalcify bone calcium to raise the plasma calcium level.
    • Deficiency of vitamin D leads to rickets in children and osteomalacia in adults
       
       
    Rickets
    • The name of Rickets is given to vitamin D deficiency after a famous English bone setter by EII. In mild deficiency of vitamin D, the symptoms shown are restlessness and irritability.
    • Rickets is a disease of infancy and childhood. Calcium and phosphorus are not deposited enough to form strong bones and as a result the leg bones become bent and deformed.
       
    Rickets Rickets
    Symptoms
    • Small round unossified areas are developed near skull bones
    • Projections are formed on the osteochondal junction of the ribs.
    • It resembles a rosary and it is known as ‘rickets rosary’.
    • The abdomen is distended and chest deformities like depression of ribs attached to diaphragm take place. This is known as Harrison’s sulcus and gives an appearance of ‘pigeon breast’.
    • In a later stage, pelvic deformities, bow legs and/or knock knees develop.
    • Nutritional rickets occur in infants and children of poor families. Premature infants are more susceptible to rickets
       
    Osteomalacia
    • Osteomalacia occurs among adults.
    • It is often known as ‘adult rickets’. Osteomalacia is most common among women who live on a poor diet lacking in calcium and vitamin D. Pregnant women are more prone to this.
    • It is mainly because of the increase in weight during pregnancy accompanied by the deficiency of vitamin D.
    • It is again common among women who observe ‘purdah’.
    • Repeated pregnancies and prolonged lactation further deplete calcium stores which results in osteomalacia.
    • Pain, softening and tenderness in the bones and fractures are the common complaints of the patients of osteomalacia.
       
    Sources
    • Best sources: Fish liver oils, egg yolk, milk, butter, ghee and fortified foods
    • Best natural source: Sun light
    Requirements
    • The daily requirements of vitamin D for infants, children, pregnant and nursing women have been estimates to be 400 IU (10µg) and for older children and adults about 200 IU (5µg).


Last modified: Tuesday, 5 June 2012, 5:47 AM