Vitamin D is a fat-soluble vitamin that actually acts more like a hormone than a typical vitamin because it’s produced in the body when the skin is exposed to sunlight. It is produced in your skin after oral absorption and exposure to sunlight and then transformed by your liver and kidneys.
I have not yet met a client who wasn’t deficient in Vitamin D - it really is a global health issue and is mainly linked to a lack of sun exposure.
Vitamin D is involved in complex interactions with your metabolism, hormones, and genes that influence your body’s ability to process sensory information and therefore also have an impact on migraines.
As I mentioned above, Vitamin D is actually more like a hormone and also plays an essential role in:
Fertility (follicle development & progesterone production)
Menstrual cycle regulation
Vitamin D is known for its crucial role in bone and muscle health and it has gotten a lot of press since the pandemic for its immune supporting properties… but it seems to be important for migraineurs too:
Vitamin D deficiency is associated with inflammation, autonomic function, autoimmune disorders, chronic pain, cancer, and vascular and neurological disorders. (Source)
Let’s break these down:
Inflammation plays a key role in migraine and can even lead to activation of the trigeminal nerve, which is known to cause migraine and headaches. Also, Vitamin D supplementation has shown to decrease inflammatory markers like CRP (C-reactive protein).
One of the most important mechanisms by which vitamin D deficiency could contribute to headache is through the possible sensitization of the second and third neurons. When neurons responsible for sensing pain become sensitized, it means that they sense pain in situations where they previously would not. So you are basically having an increased or abnormal feeling of pain.
There is strong evidence between magnesium deficiency and migraine, but magnesium also assists in the activation of Vitamin D, so it can play a role in low vitamin D levels and again migraine.
Vitamin D also reduces the production of nitric oxide (NO). Nitric oxide is a signaling molecule in the body that causes blood vessels to widen and stimulates the release of certain hormones, such as insulin and human growth hormone. NO affects neurotransmission and vasodilation and is considered a key mediator in migraine. Therefore, it is possible that vitamin D can diminish the frequency of migraine attacks by inhibiting NO synthase production.
Vitamin D also influences the release of dopamine and serotonin, which are known to be connected with migraine. In addition, Vitamin D deficiency may also cause depression, which often coexists with all types of headache.
More evidence of a potential connection between Vitamin D and headache is the presence of VDRs and the vitamin D binding protein (VDBP) in the brain. These are genetic polymorphisms (TaqI and FokI VDR) that have been shown to be associated with migraine without aura, and headache severity, most likely because of their connection with increased inflammation.
There are 2 forms of vitamin D:
Ergocalciferol, also known as D2 found in plant sources
And Cholecalciferol aka D3 found in animal sources
As usual, the animal sources are the most absorbable or bioavailable for your body and are therefore the preferred source. Vitamin D2 is rarely used, I’ve seen it added to industrial plant-based milks and yogurts in chemical form, so you can imagine that this is not something your body can work with, but it’ll just end up being excreted with urine.
Sources of Vitamin D3:
The best source is sunlight (you cannot wear a sunscreen though)
Second best are fatty fish and fish liver oils
Smaller amounts are found in egg yolks, cheese, and beef liver.
Sources of Vitamin D2:
Certain mushrooms contain small amounts
Fortified industrial milks and yogurts contain synthetic D2
Why your vitamin D levels may be low:
Blood sugar dysregulation and insulin resistance are linked to vitamin D deficiency. One study even found a direct correlation between low Vitamin D and diabetes.
Systemic inflammation is associated with lower vitamin D.
Deficiencies in vitamin K2, magnesium & boron are also associated with chronically low vitamin D.
Overuse of sunscreens and lotions with SPF, and lack of time outdoors.
If your fat digestion is not working optimally, it will impact your absorption of vitamin D (as stated above, vitamin D is a fat soluble vitamin, meaning it needs to be linked to fatty acids so that your body can absorb it)
Impaired liver or kidney function
Genetic predisposition to vitamin D deficiency: variants in the VDR gene impact absorption, metabolism and utilization of vitamin D.
So if you have been consistently supplementing with vitamin D and it’s still low or symptoms continue to persist, it’s time to start looking at other causes.
Contact me if you would like help with uncovering these.