Vitamin D or calciferol is one of the fat-soluble vitamins needed by the body. It is very essential in the absorption of calcium and phosphorus into the bones, teeth, and other body organs. Vitamin D synthesis takes place in the skin with the help of sunlight and in normal situations, this process produce the needed amounts of Vitamin D. Adequate amounts of Vitamin D guarantee strong bones and teeth, and proper nerve function. There are five forms of Vitamin D namely, Vitamin D1, D2, D3, D4, and D5. Of all these forms, the most important to humans are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Being a fat-soluble vitamin, Vitamin D is stored in the body’s fat tissues for days up to 6 months. However, excessive amounts of fat-soluble vitamins which the fats can’t handle are stored in the liver and can cause health disorders.
Daily Vitamin D needs vary according to sex, age, and special conditions. Infants need 400-800 IU, children up to 20 years old are required 400 IU, pregnant and lactating women have increased need of 400-800 IU, and people with age 51 and above should consume at least 400 IU daily. To get the ample Vitamin D supply, you must have at least three 15 min sessions under the sun every week. Synthesis of Vitamin D in the skin decreases as people goes older and many can’t produce adequate Vitamin D due to lack of exposure to sunlight. In these cases, it is important to replenish Vitamin D from dietary Vitamin D sources and Vitamin D supplements.
Foods rich in Vitamin D include liver, milk, butter, flour, cheese, egg yolk, and some fishes. However, the richest Vitamin D source is fish liver oil. Vitamin D supplements are commonly available in pill form. Both Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol) are manufactured into dietary supplements.
Vitamin D Benefits
- Vitamin D is crucial in the absorption of calcium and phosphorus. It is very essential in maintaining strong bones and teeth.
- Vitamin D regulates the immune system. It helps the body fight off common colds and flu.
- Vitamin D can prevent brain disorders when people are older. It also promotes good mental function during later life.
- Vitamin D plays a role in maintaining an ideal body weight. It also helps in weight loss.
- Vitamin D can decrease the recurrence of asthma attacks and alleviate asthma symptoms.
- According to studies, Vitamin D can prevent osteoporosis.
- Adequate amount of Vitamin D prevents dental caries.
Vitamin D Deficiency
The most common results of Vitamin D deficiency are rickets in children and osteomalacia in adults. Rickets is most likely to occur during the child’s first 6 to 18 months of life, the period of crucial skeletal or bone growth. With rickets, the bones become soft and brittle. The child is likely to experience tetany, retarded growth, bone deformities, and loss of muscle tone. On the other hand, oestomalacia occurs in women during pregnancy and lactation where there is large depletion of calcium in the mother. Vitamin D deficiency also leads to dental caries.
Vitamin D Toxicity
Large doses of Vitamin D can result in anorexia, nausea, vomiting, constipation, weight loss, and weakness. The most serious effect of Vitamin D toxicity is calcinosis or calcium and phosphorus deposits in the kidney.