EpilepsyPatient friendly summary

  •  Ultraviolet-B (UVB) light may lower the risk of diseases that may trigger epilepsy.
  • Sunlight may also reduce epilepsy risk by increasing production of other chemicals in the brain including serotonin, dopamine, and norepinephrine.
  • Vitamin D may lower the risk of diseases related to epilepsy. However, vitamin D may have little effect on epilepsy itself.

Epilepsy is a brain disorder. It involves repeated, spontaneous seizures of any type. Seizures are also called “fits” or convulsions. They are episodes of disturbed brain function. They cause changes in attention or behavior. Seizures are caused by abnormally excited electrical signals in the brain.

Risk factors

A number of diseases are risk factors for epilepsy:

  • Strokes
  • Dementia
  • Traumatic brain injury
  • Infections (HIV/AIDS, meningitis)
  • Congenital brain defects
  • Kidney or liver failure

Sunlight exposure and epilepsy risk

In England, fewer seizures were noted on bright sunny days. More seizures occurred on dull overcast days. Studies also reported higher seizure rates in the wintertime. There is less sunlight in the winter.

Light therapy is sometimes used to reduce the effects of epilepsy. It is not clear how this works. Sunlight is a source of vitamin D. Sunlight may also increase production of other chemicals in the brain including serotonin, dopamine, and norepinephrine.

Drugs used to treat epilepsy may reduce vitamin D levels.

Vitamin D and epilepsy

Vitamin D levels

The primary link between vitamin D blood levels and epilepsy arises from the use of antiepileptic drugs used in treatment of epilepsy, which lower vitamin D levels. Thus, those using antiepileptic drugs may want to have their vitamin D level checked and increase vitamin D production or intake as indicated to reach optimal levels of at least 30-40 ng/mL (75-100 nmol/L).

How vitamin D works

Vitamin D may help people with epilepsy by:

  • Increasing low bone mass density
  • Protecting against diseases that are risk factors for epilepsy

Low bone mass is a problem for people with epilepsy, which may increase the risk of fractures associated with falls.


Vitamin D may prevent some of the diseases that could lead to epilepsy. This includes meningitis, HIV/AIDS, strokes, and dementia.

Vitamin D and calcium

Vitamin D deficiency may cause hypocalcemia. Low calcium levels may trigger seizures, especially in infants. These seizures are not caused by epilepsy. However, vitamin D supplements can quickly correct the problem.


Vitamin D primarily benefits epilepsy by protecting against other diseases such as low bone mineral density.

People with seizures should check their vitamin D and calcium blood levels. The seizures may be due to low calcium levels, not epilepsy.

Find out more…

We will be adding a detailed evidence summary on this topic in the near future.  Please check back soon to find out more.

Page last edited: 17 May 2011