Vitamin D Supplements And Health Benefits

Studies during the past several decades authenticate an indispensible role of Vitamin D for human health. Vitamin D is required for adequate absorption of calcium and phosphate in our bones. It aids in proper development and remodeling of bone, cell to cell communication, control of cell growth, proper immune and neuromuscular functioning.

Some infrequent reports also suggest its association with pathophysiology of cancer, multiple sclerosis, rheumatoid arthritis, type 1 diabetes and cardiovascular disease. However, a lot of uncertainties are associated with health effects from vitamin D supplementation for these diseases.

The deficiency of vitamin D leads to a childhood disease of bones softening commonly known as “Rickets”. In this disease, bones fail to properly develop resulting in impaired bone mineralization and bone damage. In adults, vitamin D deficiency leads to “Osteomalacia” resulting in fragile bones, muscles weakness and bending of spines and legs. It has been observed that vitamin D deficiency decreases efficient calcium absorption and enhances the calcium loss from bones thereby increasing the risk for bone damages.

A large number of clinical data suggests that adequate vitamin D status enhance the bone mineral density and therefore protects against osteoporosis as well. Furthermore, inadequate levels of vitamin D can lead to an increased cancer risk, poor hair growth and weakened immune system.

Conversely, excess vitamin D can cause toxicity and allow the body to absorb too much calcium, leading to hypercalcemia. This result in an increase in urination and thirst, kidney stones, increased risk of heart attack and may lead to a syndrome of mental retardation and facial deformities in fetus during pregnancy. The toxicity of vitamin D is often caused by high doses of vitamin D supplementation (but not by sunlight exposure).

Current status of Vitamin D and Metabolic bone diseases

For decades, vitamin D has been associated with bone health and considered as an important source for preventing metabolic bone diseases and other complications caused by decreased bone density. It is well understood fact that vitamin D deficiency is associated with rickets in children and osteomalacia/osteoporosis in adults, as mentioned above. The deficiency is highly prevalent among general population in low-income countries and covers approximately 30-50% of total populations. In general, the Vitamin D insufficiency is present in every sector of the population but more prevalent among elderly people and young infants in most of the countries.

Initially, the importance of vitamin D for musculoskeletal health remained unrecognized and untreated. However, as the role of diet in the development of rickets was determined, increased emphasis was given for dietary intake of vitamin D to eradicate the disease. Low blood levels of vitamin D are also associated with increased mortality, particularly among elderly women. Apart from the low mineral bone density and osteoporosis, accumulating evidences have demonstrated that vitamin D deficiency may play an important role in infectious and chronic inflammatory diseases.

The benefits of Vitamin D supplementation for bone health appear to be marginal

A number of reports on vitamin D supplementation have reported variable results. These studies show inconsistent associations between bone mineral density and vitamin D status. The debate regarding an association between the vitamin D supplementation and the skeletal health benefits (such as prevention of bone fracture) still continues.

Recent analysis performed by researchers from the University of Auckland, New Zealand, puts a question mark to the current trend to provide certain groups of people with vitamin D supplements. The study focused mainly on published research data on the effects of vitamin D supplementation without co-administration of calcium on fracture prevention. This analysis compared the data from 23 clinical trials involving more than 4000 patients from numerous geographical locations.

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The result obtained in this study was rather surprising and suggests only negligible benefit of vitamin D supplementation on bone health. Although, at some skeletal sites small improvements in bone density were detected. It has been observed that statistically significant increase in bone density was localized only at the neck of the femur but not at the total hip region. Such a localized improvement is supposed to be artifactual, or a likelihood finding. In short, it has been suggested that single site localized effect on bone material density could not be considered as a reduction in fractures and makes very little clinical difference. In this respect, it has been suggested that we receive enough of this compound from the natural sources and thus make unnecessary the additional supplementation of vitamin D.

In short, research studies performed during last few years suggested that vitamin D supplementation provides only marginal benefits in the prevention of osteoporosis and recommend healthcare professionals to prescribe vitamin D supplements only to those people who have biochemical deficiency of this compound. Future studies are needed to analyze the effect of vitamin D supplements on bone density in terms of the dose given and the baseline vitamin D status to draw any effective conclusion.