Essay: Vitamin D deficiency and stroke

Stroke is the second most common reason of disability (about 50% will have a significant long-term disability) and second most common cause of death worldwide (26) The direct/indirect cost of stroke in 2007 was estimated to be $62.7 billion (27)
Vitamin D deficiency was highly prevalent in those study, 56.7% while 42.3% of CVA patients had optimal vitamin D level these findings were consistent with those of previous studies, which showed 78-55% prevalence of vitamin D deficiency in the Chinese acute ischemic stroke population. [28, 29] , and another studies with same environment in central Ethiopia and Northern Nigeria have reported high Prevalence of suboptimal 25OHD levels [30, 31] .
This study revealed those age significant associated with disabilities in acute stroke (P vale <0.05). This finding is similar to result of other study that show the  advancing age has a major negative influence on stroke morbidity, mortality, and long-term outcome [32,33,34,;35,36]which unmodified risk factor . The influence of age in stroke outcome is seen in both minor and major strokes
The chronic complications of DM affect many organ systems and are responsible for the majority of morbidity and mortality associated with the disease. Chronic complications can be divided into vascular and nonvascular complications, The vascular complications of DM are further subdivided into micro vascular  ( neuropathy, nephropathy, retinopathy) and macro vascular complications (coronary heart disease (CHD),peripheral arterial disease (PAD),Cerebrovascular disease )(37)
This study revealed those DM significantly associated with disabilities in acute stroke patient (Pvale <0.05) and which more disabilities in uncontrolled DM patient (Hb1ac>7) This finding is similar to result of other study that show the history of diabetes mellitus are associated with poor clinical outcome(38)  and hyperglycemia in diabetic acute stroke patients predicts a poor prognosis (38) The UKPDS demonstrated that each percentage point reduction in A1C was associated with reduction in micro and macro vascular complications. There was a continuous relationship between glycemic control and development of complications.
This study revealed those HT with not significantly associated with disabilities in acute stroke (P vale >0.05) This finding is similar to result of other study stroke in Inner Mongolia, China (39)and another study (40)(41)
In spite The smoking risk factor for IHD ,lung cancer and CVA  our study revealed those smoking  with not significantly associated disabilities in acute stroke (Pvale >0.05) This finding is similar to result of other study (42–43).
Several possible biologic mechanisms might describe the association of vitamin D deficiency with CVA , Activated vitamin D is an inhibitor of the renin-angiotensin system. (44) Lower 25(OH) D levels are related with increased risk of incident hypertension, [45] and diabetes. [46] Activated vitamin D may also delay atherosclerosis by inhibiting macrophage cholesterol uptake and foam cell development. [29]
There are several mechanisms by which Vitamin D deficiency  could exacerbate stroke injury. Vitamin D deficiency affects post stroke inflammatory responses, which play a serious role in the pathophysiology of CVA (47–48). Cerebral ischemia results in a characteristic poststroke inflammatory response, involving activation of astrocytes and immune cells, increased vascular and blood brain barrier permeability, invasion of leukocytes, and cytokine production (49, 50, 51).firstly Local immune cells (microglia) are triggered , and subsequent peripheral immune cells gain access to the CNS as a consequence of a compromised blood brain barrier and increased adhesion molecule expression on cerebral vasculature and activated immune cells (50, 52, 53). Once activated, inflammatory cells can secrete cytotoxic substances, such as further cytokines, that induce secondary damage and disseminate immune cell activation and recruitment to the ischemic site (51,  53, 54).
Our findings have confirmed the results of the previous studies, which suggested that 25(OH) D is a prognostic marker of functional outcome and death in patients with acute ischemic stroke and hemorrhagic stroke [55, 56] serum 25(OH) D level was a predictor of both the severity at admission and the discharge functional outcome in Chinese patients with acute ischemic stroke [57].  some studies have tried to demonstrate the association between vitamin D status and functional outcome of acute stroke. And a new study confirm that Low 25(OH)D level was a predictor of functional outcome at discharge and 1-year mortality in Caucasian stroke population. [58]
Among patients with stroke vitamin D deficiency is reported to predict greater severity and adverse outcomes including recurrent strokes and death [58, 59]. Vitamin D deficiency is also related with a greater likelihood of falls, poor muscle and bone strength, and possibly increased fracture risk among stroke survivors (60) These findings were consistent with those of previous studies shown that low 25(OH) D levels are predictive of future stroke (61)
This study reveal that significant associated between 25(OH) D level and disability according to NIHH score in acute stroke male patients