Mandy,
If it's any consolation, you are a very special case when it comes to controlling your cluster headaches with the anti-inflammatory regimen of Omega 3 Fish Oil, vitamin D3 and calcium citrate tablets containing magnesium and zinc.
Clearly you need to discuss this regimen with your doctors, as it is equally clear from your last post that you're already following a well-established protocol of hormone replacement with other prescribed medications, vitamins, and minerals as a result of your thyroidectomy.
Note, I say "doctors" as I doubt your neurologist is treating your thyroid condition. Accordingly, a phone consult between your neurologist and the physician treating your thyroid condition may be in order.
As you've indicated you are already taking what you call "calcitrol" (I'm making the assumption it is actually calcitriol), the suggested starting point is to ask for a blood test of 25(OH)D3, to check the serum level of this vitamin D3 (cholecalciferol) metabolite.
You may have more than enough of it already in your system… The optimal level of 25(OH)D3 we're looking for in the anti-inflammatory regimen for vitamin D3 is shown below as suggested by Dr Peter J Lewis, MD in his paper titled, "Vitamin D deficiency: more on diagnosis and management" in nmol/L:
• <100 = Deficient
• 100-200 = Optimal
• 135-225 = Normal in sunny countries
• 500+ = Potentially toxic (this would require a sustained daily intake >/= 40,000 IU for several months)
[Note: To convert to nmol/L to ng/ml, divide by 2.5]
If your 25(OH)D level is in the optimal range and you're already taking enough calcium to lay hard shell eggs, all you may need to add is the Omega 3 Fish Oil.
Why you're a special case when it comes to finding effective methods of intervention for your cluster headaches may be of interest and worth discussing with your doctors.
The short answer is the treatment protocol you're on as a result of your thyroidectomy may be affecting your arterial pH and that may be affecting the efficacy of your CH medications if your arterial pH is too low. A simple change in diet to include more alkaline forming foods may help.
See the link provided by Barry_T_Coles for a list of alkaline and acid forming foods:
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You also might want to ask your doctors for a prescription for oxygen therapy at a flow rate of 15 to 25 liters/minute with a non-rebreathing oxygen mask.
Take care and please keep us posted.
V/R, Batch