Nick,

Thanks for the update and sorry you're having such a rough time.

Ask your GP for labs of your serum calcium and PTH.  As long as your serum calcium remains within its normal reference range, there's no vitamin D3 toxicity even at 300 nmol/L (120 ng/mL).  I've run my 25(OH)D up as high as 180 ng/mL (450 nmol/L) with normal calcium levels so no toxicity.

You're likely battling an allergy.  They're frequently subclinical (no outward or obvious symptoms) but they're still there triggering mast cells to release large quantities of histamine.  The histamine in turn triggers neurons in the trigeminal ganglia and elsewhere in the CNS to express Calcitonin Gene-Related Peptide (CGRP) and other neuroactive peptides responsible for neurogenic inflammation and the pain we know as CH.

It gets worse, the CGRP in turn triggers mast cells to release even more histamine and this results in what I call a CGRP cascade.  When that happens, CH become uncontrollable with high frequency, severity and duration.  When this happens to me, I take a first-generation antihistamine like Benadryl (Diphenhydramine HCL) at 25 mg every four hours throughout the day for a week to 10 days.  No longer.

If the Diphenhydramine HCL helps reduce the frequency and severity of my CH, I start looking for the source of the allergic reaction then try to limit my exposure to it.  This much Diphenhydramine HCL will make us drowsy so If I need to drive or be sharp as a tack during the day, I wait until I'm home for the day then take 50 mg of Diphenhydramine as I walk through the door and another 50 mg at bedtime.

In this situation, it also helps to double the magnesium dose taking 400 mg in the morning and another 400 mg 12 hours later.  This helps prevent osmotic diarrhea.  Doubling the Omega-3 fish oil also helps.  If you get this far and your CH are still hitting hard and heavy, I'd start taking vitamin C at 1000 mg every 2 hours throughout the day.  Taking a couple thousand mg/day of Turmeric (Curcumin) has also helped.

The Bio-Tech D3-50 will likely prove to be the best option.  This water soluble formulation has a much higher bio-availability and is faster acting than the liquid soft gel formulations.

As to how frequently to take the 50,000 IU capsules, you'll need the results of your serum calcium lab to know for sure.  Without this lab, I would take one of the D3-50 every 3 days to see what happens.  Be sure to double the magnesium dose.

Take care and please keep us posted.

V/R, Batch

Wow!  Great posts and questions...

Nick, glad to hear the Benadryl (Diphenhydramine HCL) did the trick to kick start the anti-inflammatory regimen.  A pain free response to the anti-inflammatory regimen is the goal.  I wouldn't settle for just a reduction in the frequency of my CH so would keep tweaking the regimen until I was CH pain free.  Basically, leave no stone unturned...

The mechanism of action with Diphenhydramine is fascinating.  A first-generation antihistamine like Diphenhydramine crosses the blood brain barrier to block histamine H1 receptors at the genetic layer in neurons throughout the brain and in particular, the trigeminal ganglia where calcitonin gene-replated peptide (CGRP) is expressed.  This helps prevent the CGRP cascade cause by a flood of histamine.

It's really a numbers and probability game.  If the H1 genetic receptor is already occupied by histamine, Diphenhydramine will have little effect.  However, if the cellular concentration of Diphenhydramine is high enough, as soon as most of the H1 receptors are vacant and filled with the Diphenhydramine molecule, we start experiencing its beneficial effects.  That means we need to take the Diphenhydramine for at least a week to 10 days to make sure we plug all the histamine H1 receptors possible.

That you responded to the Benadryl (Diphenhydramine) is a great first step.  Your next step is to try and ID the offending allergen then limit or avoid further exposure.  I say this as Diphenhydramine is still a drug so its use should be limited to only as needed and not a long term solution.

Regarding magnesium...  1000 mg/day is fine... and a must if loading with more than 10,000 IU/day vitamin D3.  Splitting the dose am/pm helps prevent osmotic diarrhea..

Rgarding the Bio-Tech D3-50...  Slacker, you've got the right link.  I'm chronic CHer so take one of the 50,000 IU capsules every 5 to 7 days for an average daily dose of 7,000 to 10,000 IU/day of vitamin D3.  Episodic CHers should take one of the D3-50 capsules a week when out of cycle.  In any case, see your PCP/GP for lab tests of your serum 25(OH)D, calcium and PTH after a month taking the Bio-Tech D3-50 and annually after that.

Finally, for CHers new to this regimen... if you've been taking it for more than 30 days and have results from a recent lab test for serum 25(OH)D, please take the online survey for CHers taking this regimen.  To start this survey, click on the following link:

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

I'll be taking a harvest of this online survey database in late December to mark its 7th year in use.  That will make this study the longest of its kind in the prevention of CH.  This is exactly the kind of medical evidence physicians, neurologists, and headache specialists need to start suggesting this regimen to their headache patients...

Take care and please keep us posted.

V/R, Batch