Abstract
Here, we studied 83 unselected multiple myeloma patients from December 2007 through December 2014. Lower 25(OH) D levels (<10 ng/mL) were associated with higher number of plasma cells in the bone marrow. Supplementation of vitamin D was accompanied with a significant increase in hemoglobin (11.8 to 12.3 p = .039), leukocyte (4.9 to 5.8 p = .011), and erythrocyte (3.8 to 4.0 p = .004) levels, while thrombocytes (200.5 to 175.2 p = .036) decreased. In conclusion, the present study found a high incidence of vitamin D deficiency and insufficiency in MM patients. In myeloma patients, vitamin D levels and supplementation should be more widely taken into account.