Influence of vitamin D administration on bone ultrasound measurements in patients on anticonvulsant therapy

Background The objective of the study was to evaluate bone mass status las measured by bone ultrasound) in patients on anticonvulsant therapy, and the influence that Vitamin D administration exerts over it. Materials and methods We measured and compared the basal serum levels of 25 (OH)D3, parathyroid hormone (PTH), and phalangeal bone ultrasound (Ad-SOS), in 30 adult patients who were taking anticonvulsant drugs, with a control group of similar age and sex. We then gave the patients a large oral dose o f 3 mg (120.000 UI) of 25(OH)D3, and repeated the measurements after one mo nth. Results Basal 25(OH)D3 and Ad-SOS values were significantly lower, and PTH values significantly higher (P < 0.0001 in all), in the patient group. The low Ad-SOS values for the patients were independent of the treatment, but d irectly related to basal 25(OH)D3 levels (r = 0.45, P < 0.01). There was a negative association between PTH and 25(OH)D3 (r = -0.64, P < 0.0001), and no correlation between PTH y Ad-SOS (r = -0.20, p NS). After ingestion of t he large dose of the vitamin D, the patient group registered a significant (P < 0.0001) increase in 25(OH)D3 levels, their Ad-SOS values increased (P < 0.0001) nearly to the mean basal value of the control group, and PTH decr eased significantly (P < 0.0001). Conclusions These findings justify the need to assure adequate vitamin D in take in patients being treated with anticonvulsants, independently of the t reatment, age, sex, and activity status, in order to prevent osteomalacia.