The winter blues increase your headache risk

Do short, gray, sunless winter days get you down? You’re not alone. The science is clear: daylight-deprived winter days affect our mood. Our hunter-gatherer ancestors would say it’s time to retreat into a cozy cave for a few weeks, sleeping and eating and waiting for birdsong to announce the approach of spring.

Colloquially referred to as the "winter blues," the condition was first described by Norman E. Rosenthal, a psychiatrist at the National Institutes of Mental Health. Rosenthal coined the term “Seasonal Affective Disorder” (SAD). SAD is sometimes known as “winter depression”, which is misleading because the associated symptoms – sleeping longer, a craving for sweet things (carbohydrates) and subsequent weight gain – are the opposite of those seen in genuine, non-seasonal depression (loss of appetite, weight loss, sleeping less).

Is SAD real?

In case you were wondering: SAD is not an invention of scientists in need of validation but an actual medical problem with a metabolic explanation. Vitamin D (or lack of it) has a lot to do with it. Your body makes vitamin D from a pro-vitamin molecule in the outer layers of our skin. The process starts when sunlight penetrates through the skin and splits the pro-vitamin into a pre-vitamin. The energy provided by the ultraviolet (UV-B) rays of the sun is essential for this first step.

Our bodies get less sunlight in winter and are not able to create enough of the pre-vitamin. In fact, scientists believe that vitamin D deficiency is virtually endemic in modern homo sapiens, subspecies “couch potato”. Studies indicate that between 50 and 70 percent of the population in the northern hemisphere get too little vitamin D, rising to more than 90 percent in Scandinavia.

Multiple functions in the organism

Like most “letter vitamins”, vitamin D is metabolized (broken down) in various places in the body. Multiple body cells have receptors where vitamin D can attach to them and set processes in motion. With vitamin D being involved in so many bodily functions, a deficiency affects your health in many different ways. Vitamin D keeps your bones strong by helping your body absorb calcium and phosphorus, for instance. A deficit leads to loss of bone mass (resulting in osteomalacia and rickets). Vitamin D supports proper muscle function and cell production in the immune system. It also plays a role in thyroid hormone synthesis and insulin production in the pancreas, which is why vitamin D deficiency has been linked to an increased risk of type 2 diabetes. Vitamin D is important for mental health as well, with low vitamin D being linked to low mood.

Vitamin D and headache

An increased incidence of tension-type and migraine headache is commonly reported in associated with vitamin D deficiency. Recent research attempts to shed new light on the interactions.  

Just under 60% of a Norwegian study cohort of about 700 people were found to be severely lacking in vitamin D. The deficiency was associated with a variety of health conditions including muscle and bone pain, chronic fatigue and headache. Strikingly, serum vitamin D levels were lowest in subjects with headaches.

Migraine studies in Asia have revealed that more than three-quarters of people with migraine were deficient in the vitamin. Unsurprisingly, the phenomenon was worse in winter and the number of headache days was closely correlated with the severity of the vitamin D deficiency.

Co-occurrence of musculoskeletal complaints and headache is also documented in several studies. A paper by Sanjay Prakash et al. reports that people with chronic tension-type headache had significantly lower levels of vitamin D in their blood than symptom-free subjects.

Prevention is better than cure

When it comes to preventing vitamin D deficiency, you are your own best doctor. The most obvious solution is also the cheapest: get out into the fresh air as often as you can for as long as you can and get the most out of every ray of sunlight. Even winter has its share of sunny days. Why not head outside for a walk on your lunch break? Sunny weather and mild temperatures are the perfect opportunity to get out and soak up some energy. You might be able to postpone some of the work you’d planned for that time until the evening hours. This will make it easier for your body to reduce your vitamin deficit.

However, these efforts on their own may not be quite enough to correct a lack of vitamin D. Using daylight lamps to support and stimulate vitamin D production now has medical backing. A German Medical Association guideline recommends the use of daylight lamps for SAD and considers their effectiveness to be proven by studies.

Vitamin D medications should be saved as a last resort when all other preventive measures have failed. Even then, they should only be used under careful medical guidance and for a very limited period of time, and only if the benefits outweigh the risks. This will help ensure that reaching for drugs does not become your standard response to deficiency issues.

Here’s hoping science will soon come up with a few more ideas to stave off those winter blues. But true relief comes only when the days grow longer and the sun finally shows up with all its life-giving light, soothing and invites us to soak up some vitamins. Until then, the best advice – especially if you tend to get headaches – is to get out and do things outdoors and take in every precious ray.