While well known as a significant factor in overall health, vitamin D deficiency could influence the occurrence of frequent headaches, especially in patients underexposed to sunlight.
Given that dietary vitamin D has been identified in the development of various neurovascular diseases, such as neurocognitive decline and ischemic stroke,1,2 it was a matter of time before vitamin D sufficiency would be examined for its role in the onset of headaches.
Results of a Finnish study offered the possibility that a deficiency in vitamin D may contribute to frequent headaches, especially in men underexposed to sunlight.3
The study, published in Scientific Reports, is one of first to examine the possibility that hypovitaminosis D may offer one explanation and an easy solution for some with frequent headaches.
In particular, men who had the lowest serum levels of vitamin D were far more likely to suffer from frequent headaches in comparison to those with the highest circulating vitamin D levels.3
“There is some data that headaches are more prevalent in higher latitudes and less prevalent during the summer months”, said Jyrki K. Virtanen, PhD, from the University of Eastern Finland in Kuopio, Finland. “Both of these [factors] are related to UVB exposure from the sun, and therefore to vitamin D because skin produces vitamin D when UVB exposure is strong enough.”
Vitamin D Insufficiency: Role in Frequent Headaches?
Sun exposure could be a significant factor in vitamin D levels among the 2601 Finnish men, aged 42-60 years, whose serum vitamin D was measured. These men were participating in a population-based Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) based in eastern Finland.4
In Nordic countries including Finland, a person can only produce vitamin D from sun exposure during a limited number of summer months, similar to that seen in the Northeastern United States. Given this, serum levels of vitamin D would be typically low during the winter months, especially if a person does not have an adequate intake of vitamin D through their diet or supplementation, Dr. Virtanen told Practical Pain Management.
“Also, in our study, we found that frequent headaches were less prevalent among those men who had given their blood sample and filled out the questionnaire about headaches during the summer months,” Dr. Virtanen noted.
By collecting fasting venous blood samples from the patients and using demographic data taken from the KIHD, researchers were able to search for univariate relationships between serum 25(OH)D and baseline characteristics of the study population.
Patients who had lower serum 25(OH)D concentrations typically were younger and had less leisure time physical activity, a lower income, and overall poorer self-reported health;3 they also tended to be smokers.
While the whole study population showed an average serum 25(OH)D concentration of 43.4 nmol/L (SD 18.9, min-max 7.8-136.1 nmol/L), there was a noticeable difference in vitamin D levels when comparing patients with frequent headaches to those who did not register a problem with recurring headaches.3After adjusting for age and year and month of blood draw, patients with recurring headaches had an average serum 25(OH)D concentration of was 38.3 nmol/L (SD 18.8), while patients no headache complaints had an average of 43.9 nmol/L (SD 18.9) (P for difference < 0.001).
Two hundred and fifty (9.6%) of the men reported experiencing frequent headaches, and for those within the lowest serum 25(OH)D quartile, they appeared to have 116% higher odds (OR 2.16; 95% CI 1.49-3.13) of developing repeated headaches.
“Because this was an observational study, we can’t say that low serum vitamin D was the cause of the frequent headaches,” said Dr. Virtanen. “For example, those who suffer from frequent headaches may be less likely to spend time outdoors and would thus be less exposed to the UVB light.”
The data also may suggest that only those with very low vitamin D levels could be more susceptible to headaches, given the higher risk of headaches observed in this group, Dr. Virtanen explained.
Clinical Opportunities in Headache Management
Regardless, keeping serum vitamin D at a healthy level during the winter months is something clinicians might recommend to their patients, Dr. Virtanen noted, and it can be done through proper diet and/or supplementation.
Also, screening for vitamin D deficiency in patients who present with chronic headache symptoms may be a viable opportunity. According to Dr. Virtanen, not only might this help clinicians determine if headache symptoms are related to inadequate vitamin D, but a low vitamin D status could be significant in assessing a patient’s overall health.
While there is evidence that a deficiency in vitamin D levels may precipitate headache frequency, researchers are trying to determine the clinical effectiveness of vitamin D supplementation as a treatment for complaints of chronic headache. Dr. Virtanen and his colleagues currently are conducting the Finnish Vitamin D Trial (FIND), a 5-year study to investigate the possible benefits and risks of vitamin D supplementation for general health trajectory and disease outcomes among 2500 people.
“Among other chronic diseases, one of our goals is to investigate the effects of vitamin D supplementation on pain,” Dr. Virtanen told Practical Pain Management. The expectation is that this study, which will conclude at the end of 2018, may add better long-term understanding about the role of vitamin D supplementation in patients with chronic headaches and other chronic pain conditions. Also, it may confirm a possible function of vitamin D in the context of a patient-population underexposed to sunlight during the winter months.
Rashid Giniatullin received a research grant from the Academy of Finland. No other authors offered financial interests with regard to this study.
- Basit S. Vitamin D in health and disease: a literature review.Br J Biomed Sci.2013;70(4):161-72.
- Schlögl M, Holick MF. Vitamin D and neurocognitive function.Clin Interv Aging. 2014; 9: 559–568.
- Virtanen JK, Giniatullin R, Mäntyselkä, P, et al. Low serum 25-hydroxyvitamin D is associated with higher risk of frequent headache in middle-aged and older men. Published online ahead of print. January 3, 2017;7:3969.
- Kuopio Ischaemic Heart Disease Risk Factor Study.Ann Clin Res. 1988;20:46-50.