Link between Vitamin D and Cardiovascular Diseases Cardiovascular Pharmacology: Open Access

Over the last decades, cardiovascular diseases (CVD) effect is increasing very fast. This review article discuss the association between low level of 25-hydroxy vitamin and cardiovascular diseases. This review also tells us the direct effect of vitamin D on heart or on cardiovascular system may also be involved. Apart from regulating blood pressure, vitamin D also regulate endothelial and smooth muscle cell muscles, most studies support 25 (OH) vitamin D having protective effects on cardiovascular system. However this association of vitamin D and cardiovascular diseases is based on observation & ecological studies and thus is a matter of controversy. Adequate clinical data are not available to confirm these association. Unopposed activation of RAAS & generation of angiotensin promote arterial stiffing & endothelial dysfunction that proceed & contribute to the development of hypertension & also predictors of CVD risk.


Introduction about Vitamin D
Vitamin is also called calciferol. It exist in two form vitamin D2 and vitamin D3 which are called ergocalciferol and cholecalciferol. Vitamin D 3 is also called "Sunshine vitamin" because this vitamin is synthesized in epidermis cell through UV radiation and it is also consumed from fish oil and supplements [1,2]. Deficiency of vitamin D is very common problem very often unrecognized and untreated, association with osteoporosis, muscles weakness, growth retardation in children, dental caries and also increase the risk of bone fracture in adults [2][3][4][5][6].

Sources of Vitamin D
Vitamin D is obtained from man dietry sources like fatty acid fish or through the conversion 7-dehydrocholesterol as a pre-hormone in the skin from exposure to sun rays. Vitamin D is also obtained from plant in the form of ergosterol [6][7][8][9][10].

Level of Vitamin D in our Body, Effects of Vitamin D and Requirement of Vitamin D in our Body
Requirement of vitamin D in our body is based on health recommended dietry allowance are 600 IU/d for individuals aged 1 to 70 years and 800 IU/d for older than 70 years under condition of minimum sun exposure. A survey is done by NHANES (National health& nutrition examination survey) which indicate that deficiency of vitamin D exists in more than half of US middle-aged & older women and more than a third of similarly aged men. In African-Americian individuals because of darkly pigmented skin there is less synthesis of vitamin D in response to sun exposure and also black have lower dietary & supplemental vitamin D intake than white [10][11][12][13].

Mechanism by which vitamin D prevent CVD
The mechanism for how vitamin D prevent CVD is not clear but several mechanism has been proposed individuals. Such as: Receptors of vitamin D are present throughout the vascular system including endothelial cells, vascular smooth muscles & cardiomyocytes which produce 1-α-hdroxylase enzyme. This enzyme converts 25hdroxy vitamin D to calcitriol and this is the natural ligand of vitamin D receptor.

Physiology of vitamin D
Than circulating vit D 1 , 25 (OH)2 enters into the cells where it needed, either in free form or in binding form.

Links between Vitamin D and CVD
The main aim of this article is to explain the association of vitamin D deficiency & CVD.
Deficiency of vitamin D can cause endothelial dysfunction, proliferation of smooth muscle cells, formation of foam cells, artherosclerosis.
The other function of vitamin D is glycemic control, insulin secretion & sensitivity, lipid metabolism, prevention of secondary hyperparathyroidism.

Requirements of Vitamin D in our Body
According to institute of medicine (IOM) the current vitamin D requirement is as follow • 200 international unit (IU) per day for adults age 50 and younger.
The exact amount of vitamin D is not clear known, however man physician are now recommended 1000 IU to 2000 IU daily for mist adults.
The extra amount of vitamin D can increase calcium absorption, which can cause kidney stone or kidney damage.

Uses of Vitamin D
Vitamin D has also been associated with prevention and treatment of diabetes, cancer, osteoarthritis and immune system disorder.
A growing number of studies support that low level of vitamin D increased the chances of heart diseases and that addition of vitamin D supplements can decrease the risk.

Conclusion
Several trials are done to know the connection between vitamin D deficiency and CVD but there is not yet any clear conclusive evidence.