Epileptics seem to have an increased risk of insufficient vitamin D supply

A new US study reports that many patients with epilepsy using antiepileptic drugs are vitamin D deficient and have a higher risk of poor bone health and fractures.

The observational study measured the blood vitamin D concentrations of 596 epilepsy patients with a mean age of 41 years treated with antiepileptic drugs (1). The findings showed that 45% of the patients were vitamin D deficient (less than 20 ng/ml) – a higher rate of deficiency than in the general US population (32%). The vitamin deficiency levels differed according to the type of antiepileptic drugs (AEDs) the patients were treated with: more than half (54%) of those on enzyme-inducing AEDs were vitamin D deficient, compared to 37% on non-enzyme inducing AEDs. The osteoporosis risk was often exacerbated with long duration AED treatment. Epilepsy patients were also two to six times more likely to suffer fractures due to a number of factors, including seizures, impaired balance, inactivity, low bone mineral density and inadequate calcium intake.

The researchers commented that vitamin D levels in patients with epilepsy should be continuously monitored as part of routine management, and calcium supplementation should also be considered – given the higher risk of osteoporosis and fractures in this population. Beyond impairing bone health, animal and human studies suggest that vitamin D deficiency may worsen seizures (2). However, more research is needed to confirm these observations.

1. Teagarden D. L. et al. Low vitamin D levels are common in patients with epilepsy. Epilepsy Research. Published online September 2014.
2. Lazzari A. A. et al. Prevention of bone loss and vertebral fractures in patients with chronic epilepsy – antiepileptic drug and osteoporosis prevention trial. Epilepsia. 2013; 54(11):1997–2004.