Tension-type headaches are often described as a constant pressure, as if the head were being squeezed. The pain typically radiates to the head from the neck or even the lower back, the eyes and usually, but not always, affects both sides of the head. The pain is typically mild to moderate, but may be severe.
Tension headaches account for almost 90% of all headaches. However, it is not clear which comes first, the tension or the headache. As of 2013, tension headaches affect about 1.6 billion people (20% of the population). They are 30% more common in women than men.
In 2010, researchers from India, led by Dr. Prakash, hypothesized tension headaches may be related to vitamin D. Like I did with autism, they used epidemiological data, such as latitude and season-of-the-year, to formulate their hypothesis. It turns out that tension headaches are less common around the equator and less common in the summer than the winter.
Now the same group, led by Dr. Prakash, did a case-control study of 100 patients with tension headaches. The 100 subjects with headache had a 25(OH)D of 15 ng/ml compared to 27 ng/ml in the controls. Even more interesting, the patients with headache were more likely to have neck and back pain, fatigue and lower extremity weakness. They also found very strong correlations of 25(OH)D with muscle pain and bone pain.
In other words, some patients with “tension headache” may have osteomalacia (adult rickets). However, my experience in treating tension headache (or fibromyalgia) with vitamin D supplements is not as robust as their findings. It may be that sunshine, with all its benefits, is the key.
John Cannell, MD. Chronic tension headache may be a symptom of vitamin D deficiency. The Vitamin D Council Blog & Newsletter, 5/2017.