An English Physician Dr. Daniel Whistler first described rickets in 1645. In 1861, Trousseau of France linked rickets with lack of sun exposure and faulty diet. The main source of vitamin D is cutaneous synthesis. Approximately 1 billion people worldwide have low levels of 25-hydroxyvitamin D. Vitamin D is actually a steroid that has a hormone-like function. Vitamin D from dietary sources and from sun exposure of skin is stored in fat cells and is brought into circulatory system.
Current research suggests that vitamin D deficiency may also be linked to the development of hypertension, depression, multiple sclerosis, arthritis, type 2 diabetes, cardiovascular disease, and an increased risk of cancer. The recent evidence suggests that vitamin D and calcium homeostasis may also be important for a variety of nonskeletal outcomes including neuromuscular function, psoriasis, multiple sclerosis, colorectal and prostate cancer.
Effect of Vitamin D Deficiency:
Diabetes Mellitus: Vitamin D supplementation would improve glycemic control in patients with type 1 diabetes mellitus who have vitamin D deficiency. β-cell dysfunction and insulin resistance is also associated with low vitamin D levels and substantial improvement in hemoglobin A1c (HbA1c) levels with the reversal of vitamin D deficiency. Vitamin D deficiency increased insulin resistance, decreased insulin production. Vitamin D replenishment improves glycaemia and insulin secretion in patients with type 2 diabetes with established hypovitaminosis D.
Vitamin D deficiency is known to cause several bone diseases including: Rickets, Osteomalacia, Osteoporosis. vitamin D deficiency was found to be associated with psychiatric and neurological disorders like Alzheimer’s Disease, depression. It has been suggested that insufficient vitamin D may also be a reason for hypertension and increased risk of Sudden Cardiac death related to a poor vitamin D status suggest a link to cardiac arrhythmias. Cardiomyopathy due to vitamin D deficiency in infants is a rare but potentially fatal manifestation of hypovitaminosis.
Gestational Diabetes Mellitus: vitamin D depletion has been associated with reduced fetal growth in animals, The presence of insulin resistance in human pregnancy is also well established, administration of vitamin D to pregnant women with gestational diabetes transiently decreased fasting glucose levels, while, surprisingly, the level of insulin also decreased. Anti-Cancer action studies have shown Vitamin D plays a role in the prevention of colon, prostate, and breast cancers. One study of Finnish smokers, three-fold higher risk of developing pancreatic cancer. Colorectal cancer mortality is inversely related to serum vitamin D concentrations. Renal protection Vitamin D deficiency is risk factor for Sudden cardiac death and Cardiovascular event in diabetic haemodialysis patients. Vitamin D is also nephroprotective in experimental diabetic nephropathy.
Autoimune disease: vitamin D prevent systemic lupus erythematosus (SLE) in mice, allergic encephalomyelitis, collagen-induced arthritis, Lyme’s disease, inflammatory bowel illness and autoimmune diabetes in non-obese diabetic mice vitamin D agonists are synergistic with immunosuppressive agents such as cyclosporine A, mycophenolate mofetil and sirolimus in murine models of graft tolerance. Prevention against infectious disease more episodes of respiratory and skin bacterial infections with vitamin D deficiency as compared to healthy individuals including Diarrhea and tuberculosis.
Vitamin D obtained from sun exposure, food, and food supplements.
- Malnutrition: Breast milk is low in vitamin D and social customs and climatic conditions can prevent adequate UVB exposure. Cereal-based diets with limited access to dairy products cause deficiency.
- Obesity: Vitamin D is a fat soluble vitamin, and in obese patients there is more fat and most of the vitamin D is deposited in fat and not available to the body.
- Sun Exposure: The use of sunscreen inhibit more than 95% of vitamin D production in the skin because Ultraviolet rays not reach the skin
- Darker Skin Color: It has been suggested the reduced pigmentation of light-skinned individuals results in higher vitamin D levels and that, because melanin acts like a sun-block. Dark-skinned individuals, in particular, may require extra vitamin D.
- Malabsorption: patients suffering from chronic diarrhea due to any cause in ability to absorb vitamin D.