Over the past few years, our lifestyle has changed tremendously. Skipping meals, increased intake of caffeine containing beverages, sedentary lifestyle, decreased exposure to sunlight – all these factors are not just responsible for the increasing incidence of obesity and diabetes in the population but also for many deficiency diseases. Vitamin D is one such common deficiency that could lead to a myriad of health problems.
Vitamin D (calciferol) belongs to a group of fat soluble secosteroids. In humans, vitamin D is unique because of its functions as a prohormone as well as its synthesis to vitamin D3 in the body when exposed to adequate sunlight.
Vitamin D regulates the concentration of calcium and phosphate in the body and promotes healthy growth and remodelling of the bone. Vitamin D prevents rickets in children and osteomalacia in adults. Along with calcium, it protects elder adults from osteoporosis.
Vitamin D also affects neuromuscular functions, causes inflammation and influences the action of many genes that regulate proliferation and apoptosis of the cells. Vitamin D is also essential for the healthy growth of hair follicle as well as for a healthy immune system. Vitamin D deficiency is the main cause of rickets in young infants because breast milk is low in vitamin D and so is the cereal based diet.
Vitamin D deficiency is known to cause several bone diseases like:
- Rickets, a childhood disease characterised by impeded growth and deformity of the long bones. The earliest sign of subclinical vitamin D deficiency is abnormal softening or thinning of the skull
- Osteomalacia, a bone-thinning disorder that occurs exclusively in adults, and is characterised by proximal muscle weakness and bone fragility
- Osteoporosis, a condition characterised by reduced bone mineral density and increased bone fragility
- Naturally dark skinned people
- Elderly & people who are housebound
- People who cover their skin for religious or cultural reasons
- Babies & infants of vitamin D deficient mothers, especially breast fed babies
Human body makes vitamin D when the skin is directly exposed to the sunlight. That is why vitamin D is often called as the ‘sunshine’ vitamin. Ten to fifteen minutes of sunshine three times weekly is sufficient to meet your body’s vitamin D requirement. Most people meet at least some of their vitamin D needs this way.
Without sufficient vitamin D, which is crucial for calcium absorption in your intestines, your body cannot absorb calcium, thus rendering calcium supplements useless. Sunscreens, even the ones like SPF-8 block your body's ability to generate vitamin D by 95%. Therefore, sunscreen products can create critical vitamin deficiency in the body.
Natural sunlight rays responsible for generating vitamin D in your skin cannot penetrate glass. Therefore, your body can not generate vitamin D from the sunlight you receive while sitting in your car or home.
25 hydroxyvitamin D level of 20 ng/ml (nanogram/mililitre) in serum is desirable for bone and overall health. Vitamin D intake lower than 100 International Unit (IU)/day is associated with increased risk of hip fracture.
Oral vitamin D replacement or intramuscular injections are prescribed to treat Vitamin D deficiency.