Vitamin D is a hot but controversial topic in medicine today. While vitamin D plays a role in bone health, there is inconsistent data on its role in other medical conditions such as cardiovascular disease, autoimmune diseases, cancer and chronic pain. While we are waiting for more studies to clarify these associations, many individuals are asking their doctors to have their vitamin D levels checked. With all the links between vitamin D and various health concerns, it made me wonder whether an association with headaches has been examined. We will look into this further, but let's start off with a short review of vitamin D.
Vitamin D Basics
Vitamin D is a fat soluble vitamin that exists in two forms:
• cholecalciferol (vitamin D3): derived from ultraviolet light penetrating the skin and present in oily fish such as salmon and tuna.
• ergocalciferol (vitamin D2): derived from the fungal sterol, ergosterol, and found naturally in sun-dried, shiitake mushrooms.
Both forms of vitamin D are used in the fortification of foods and in vitamin D supplements.
Vitamin D Deficiency
When individuals are vitamin D deficient, the parathyroid hormone levels can increase, causing calcium to be leeched from the bones. This leads to bone weakening and causes rickets in children, and osteomalacia in adults. Osteomalacia is characterized by low blood calcium, phosphorous, and vitamin D levels. Patients with osteomalacia can have diffuse bone and muscle pain and weakness.
If your doctor decides to check your vitamin D status, he or she will measure your 25-hydroxyvitamin D level. A number of medical conditions can predispose individuals to vitamin D deficiency. Examples include: malnutrition, low sunlight exposure, kidney or liver disease, and malabsorption, as in Celiac disease. While there is no consensus on the optimal level of vitamin D, most experts believe that a 25-hydroxyvitamin D level under 20 nanograms per milliliter or ng/mL is deficient.
Vitamin D and Head Pain
Is there an association between headaches and vitamin D? Maybe. In 2009, two researchers in India published a paper in Headache — a case study on 8 patients with both vitamin D deficiency and chronic tension-type headaches as defined by the International Classification of Headache Disorders (ICHD-II). All the patients in the study had very low vitamin D levels (25-hydroxyvitamin D levels <10ng/mL), and had little to no relief of their headache with conventional drugs. The patients were supplemented with daily vitamin D (1000-1500IU) and calcium (1000mg), and obtained relief within a few weeks of therapy. The researchers felt that the vitamin D — not the calcium — was more essential to headache relief due to the timing of the relief. They explained that calcium levels typically return to normal within a week, but the patients did not feel relief of their headache for 4-6 weeks, which is when their Vitamin D levels started returning to normal.
In another study in The Journal of Headache Pain, researchers found that with increasing latitude (moving closer to the North and South Pole and farther away from the equator), the prevalence of headaches, both migraines and tension-type headaches, increased. The increase in latitude (or the farther you get from the equator) correlates with less intense and shorter duration of sunlight. With less sunlight, there is less vitamin D absorption.
What Does This Mean?
Remember — and this is key — that a link or association does not mean that one causes the other. The big picture here is that low vitamin D may contribute to head pain. Headaches may be more common in individuals who live farther from the equator where there is less sunlight. Overall, more studies are needed to better determine this relationship.
What Should I Do?
Being aware of this potential association between headaches and vitamin D will make you a more informed patient. Certainly, if your headaches are resistant to medical therapy, communicate this with your healthcare provider. Discuss her/his opinion on vitamin D or other alternative therapies for your headache. Be proactive in your healthcare.
Headache Classification Subcommittee of the International Headache Society. "The International Classification of Headache Disorders: 2nd Edition". Cephalalgia 2004;24 Suppl 1:9-160.
Holick MF. Vitamin D deficiency. N Eng J Med. 2007 July;357(3):266-81.
Holick MF, Binnkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011 Jul;96(7):1911-30.
Prakash S, Mehta NC, Dabhi AS, Lakhani O, Khilari M, Shah ND. "The prevalence of headache may be related with the latitude: a possible role of Vitamin D insufficiency?" J Headache Pain. 2010 Aug;11(4):301-7
Prakash S, Shah ND. "Chronic tension-type headache with vitamin D deficiency: casual or causal association?" Headache 2009 Sept;49(8):1214-22