Epileptic seizures result from abnormal electrical activity in the brain. About 50 million people worldwide have epilepsy. Onset of new cases occurs most frequently in infants and the elderly. About 3% of people will be diagnosed with epilepsy at some time in their lives.
Congenital and developmental conditions are mostly associated with it among younger patients; tumors are more likely over age 40; head trauma and central nervous system infections may occur at any age. Up to 5% of people experience seizures at some point in life.
Epilepsy is usually controlled, but not cured, with medication. However, over 30% of people with epilepsy do not have full seizure control, even with the best available medications. Neurosurgery may be considered in difficult cases. Anything that reduces the rate of seizure would be welcomed.
What’s the evidence for a link between vitamin D and epilepsy? Let’s take a look:
Seizures are more frequent in the winter.
Motta E, Gołba A, Bal A, Kazibutowska Z, Strzała-Orzeł M. Seizure frequency and bioelectric brain activity in epileptic patients in stable and unstable atmospheric pressure and temperature in different seasons of the year–a preliminary report. Neurol Neurochir Pol. 2011 Nov-Dec;45(6):561-6.
As early as 1988, a researcher in Nigeria noted that the brain is “electrically” more stable in the summer than in the winter and attributed the difference to summer sunshine.
Danesi MA. Seasonal variations in the incidence of photoparoxysmal response to stimulation among photosensitive epileptic patients: evidence from repeated EEG recordings. J Neurol Neurosurg Psychiatry. 1988 Jun;51(6):875-7
Febrile seizures in children are more likely during influenza season (winter), but no one has proposed that wintertime vitamin D deficiency may be behind both the influenza and the febrile seizures.
A small pilot study showed that vitamin D reduced seizures.
Recently, Drs Choong Fong and Catherine Riney of the Mater Children’s Hospital in Australia published a paper about children with epilepsy in Queensland.
They studied 111 children with seizures in Brisbane, latitude 27 degrees south. Even though it is relatively close to the equator, they found suboptimal 25(OH)D levels. The levels of the children ranged from 8 to 60 ng/mL, with a median of 26 ng/mL. Twenty-two percent had 25(OH)D levels below 20 ng/ml and 63% had levels less than 30 ng/ml.
They also found that children on more than two antiepileptic drugs or with genetic epilepsy were more likely to have levels less than 20 ng/ml.
The two authors concluded,
“Given the potential benefits of correcting vitamin D deficiency and the absence of evidence of harm associated with correcting to physiological levels; vitamin D monitoring and supplementation is important in the management of children on long-term antiepileptic drugs in Queensland.”
It is also time for randomized controlled trials using vitamin D in epilepsy.