Hey Jodee,
As the guy who's been developing and using the anti-inflammatory regimen with 10,000 IU/day vitamin D3, 1000 mg/day Omega-3 Fish Oil and the vitamin D3 cofactors since Oct 2010 to prevent my cluster headaches... I think I can give you a good explanation.
From the data collected to date from over 400 CH'ers here at CH.com and over 165 who responded to an online survey of anti-inflammatory users... the efficacy of this regimen to significantly reduce the frequency, severity and duration of cluster headaches is at least 80%... 70% experience a pain free response... and there have been no serious side effects reported that required medical attention.
This is a very healthy regimen of vitamins and minerals with many other health benefits making it something all should take. If you're curious about that, just check out the following link at vitamindwiki: Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

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In particular, read through the column at the left on the home page titled "Health Problems and D"
The 10,000 IU/day vitamin D3 we take as part of this regimen may sound high... it's not. Vitamin D3, a.k.a. the sunshine vitamin, is made in the skin for free... if exposed to the UV-B in mid day sun wearing a bathing suit without any sun block. 20 minutes exposure to sunlight under these conditions results in the skin generating up to 20,000 I/U of vitamin D3... your maintenance dose of vitamin D3 is only 10,000 IU/day.
If you're like nearly all of us... you don't run around in the mid-day sun clad in a bathing suit without any sun block... That means you are very likely vitamin D3 deficient. The normal reference range for the 25(OH)D lab test is 30 to 100 ng/mL, (75 to 250 nmol/L).
If you were a healthy Southern California Lifeguard, you would would average a 25(OH)D serum concentration of 110 ng/mL during the summer months.
One of the benefits of vitamin D3 is auto-regulation. As the body generates vitamin D3, it is also capable of regulating it's production and metabolism. This makes it very difficult to overdose on vitamin D3 or force your 25(OH)D serum concentrations too high into a toxic region. It would required more than 50,000 IU/day vitamin D3 for several months to reach the lower threshold of vitamin D3 intoxication, ~ >200 ng/mL. We shoot for a target 25(OH)D serum concentration range of 60 to 110 ng/mL in order to remain pain free from cluster headache as illustrated in the following chart:
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The data collected to date suggest a clear causal relationship between cluster headache and a vitamin D3 deficiency. CH'ers tested for 25(OH)D prior to starting the anti-inflammatory regimen with 10,000 IU/day vitamin D3, averaged a serum concentration of 26.5 ng/mL, (66.25 nmol/L). CH'ers who experienced a favorable response to this regimen averaged a 25(OH)D serum concentration of 81.4 ng/mL, (203.5 nmol/L).
The following link contains a complete list of the supplements used in this regimen along with a "How To" guide in taking them.
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Please feel free to ask questions.
Take care and please keep us posted.
V/R, Batch