###### Abstract  
Calcium deficiency is frequently observed in stroke survivors, but no data exist concerning the relationship between calcium and rehabilitation outcome in patients with stroke. Therefore, we examined in a group of subacute stroke patients if changes in the Barthel Index after a rehabilitation treatment were associated with blood parameters related to calcium status. We retrospectively explored serum calcium status (total calcium, ionized calcium), serum total protein status, and serum albumin percentage in 30 subacute stroke patients admitted to our rehabilitation center. Patients underwent a 6-week rehabilitation treatment (each session lasting 45 min, 2 sessions/day, 6 days/week). Overall, 26.7% of patients had total calcium levels below the reference range, whereas 100% of patients had ionized calcium in the reference range. Total protein and albumin were below the reference range in about 77% and 67% of patients, respectively. We found that only total calcium was correlated with the change from baseline of the Barthel Index (BI) (rho = 0.466, \(p\) = 0.009). A multiple linear regression model confirmed that in our sample the total calcium significantly predicted the change from baseline of the Barthel Index (F5, 24 = 4.074, \(p\) = 0.008, adj. R2 = 0.346). This study suggests a possible connection between serum calcium status and total protein status of stroke patients undergoing rehabilitation treatment and rehabilitation outcomes. Further investigations are necessary to confirm the importance of testing serum calcium status of patients at admission in a rehabilitation unit for an eventual supplementation or a dietary personalized program. calcium; stroke; rehabilitation; nutrition +
Footnote †: journal: Medical  
human body are strictly controlled, as are other essential metals, and regulated by three hormones: parathormone, calcitonin, and Vitamin D [6]. If levels of calcium are low for long periods, people may develop dry and scaly skin, brittle nails, and coarse hair. Muscle cramps involving the back and legs are common. These symptoms disappear if the calcemia status is restored. For a good level of serum calcium, a controlled diet together with adequate level of Vitamin D are generally sufficient. A period of hypocalcemia status that is too long can affect the brain and cause neurologic or psychologic symptoms, such as confusion, memory loss, delirium, depression, and hallucinations, as well as osteoporosis problems. This condition can be affected by other causes, such as a low level of parathyroid hormone (hypoparathyroidismroidism), pancreatitis, low magnesium levels, or certain drugs [6]. For this reason, adequate calcium levels are important for all subjects but have to be particularly controlled during ageing, especially for bone health. A very recent study on 84 patients with acute ischemic stroke was performed to determine if admission calcium status was associated with stroke outcomes after systemic thrombolysis [7]. Patients with low admission calcium who received systemic thrombolysis more frequently, required also endovascular therapy. This result could represent unique thrombosis physiology, which deserves further investigation. While limited by small numbers, these patients with low calcium also showed a trend towards worse observed clinical outcomes [7]. A study on 659 patients with an ischemic stroke showed that higher serum calcium levels measured at 72 to 96 h from insult was associated with lesser stroke severity and better 3-month functional and independence outcome [8]. In this study, the highest quartile calcium levels were associated with a higher score on the Barthel Index scale -a measure of independence in activities of daily living-3 months after the acute event. However, to the best of our knowledge, the relationship between calcium levels and the outcome of a rehabilitation intervention was not investigated.