Vitamin D deficiency has been linked to many health disorders, ranging from cancer to cardiovascular disease, but there appears to be no association between levels of Vitamin D and migraine or headache severity, according to a new study.

Prior research has provided conflicting information about a possible link between vitamin D deficiency and chronic or recurrent painful conditions such as migraine. The most recent study, at an Iranian neurology clinic, compared 73 migraineurs to 98 individuals without migraine, and found no such link.

Researchers, led by Alireza Zandifar of the Isfahan University of Medical Sciences in Isfahan, Iran, evaluated Vitamin D levels in both the migraineurs and controls and found no relationship between vitamin D concentration and frequency of headaches, presence of nausea, a family history of migraine, duration of headache, and headache aggravation with menstruation.

The researchers also evaluated several subgroups, including gender, age, duration of daily sun exposure, and place of residence. While men typically had higher Vitamin D levels than women, researchers found no differences between migraineurs and the control group when they evaluated men and women separately. Additionally, they found no significant difference between cases and controls with the same daily sunlight exposure, among patients under the age of 25 compared to older patients, and between patients under the age of 50 and older patients. There were also no significant differences between subjects from rural and urban areas. Not surprisingly, researchers did find that those with less sun exposure had lower levels of Vitamin D than study participants with more sun exposure.

The authors recommend that studies with larger sample sizes and randomized double-blind clinical trials should be performed to confirm their findings.

The study appeared in the journal BioMed Research International.