Shooky,
Good question on why we need calcium supplements while taking the anti-inflammatory regimen with 10,000 IU/day or more vitamin D3. I'll do my best to answer it.
In order to understand the need for supplemental calcium, particularly when taking vitamin D3 at doses of 10,000 IU/day or more, and resulting serum concentrations of 25(OH)D (60 to 110 ng/mL) needed to control cluster headache, we first need to understand the word
homeostasis and then
calcium homeostasis...
Wikipedia has a good definition of homeostasis... "It's the property of a system that regulates its internal environment and tends to maintain a stable, relatively constant condition of properties such as temperature or pH.
It can be either an open or closed system. In simple terms, it's basically a process in which the body's internal environment is kept stable."
Did you ever wonder why or how, under normal conditions, we all maintain a body temperature of 98.6º F ? The answer is body temperature is controlled by a complex set of homeostatic processes.
Serum pH, a topic I've discussed on several occasions as it appears cluster headaches are also sensitive to changes in serum pH, is another classic example where homeostasis comes into play.
Our normal reference range for arterial pH at 7.35 to 7.45 is tightly controlled by two overlapping homeostatic processes.
Changes in respiration rate and associated blood flow is the most immediate of these two processes as an increase respiration rate and tidal volume of breath can elevate arterial pH in as little as a few seconds up to a minute or two depending on the depth of hyperventilation.
During hyperventilation, we blow off CO2 faster than our bodies generate it through normal metabolism... As CO2 disassociates into carbonic acid when dissolved in water, excess CO2 means higher acid content (lower pH).
Accordingly, by intentionally hyperventilating, we blow off CO2 from the lungs and lower the acid content of arterial blood. As this removes hydrogen ions from the blood, we elevate our arterial pH. (If you didn't take chemistry... pH is the negative logarithm of the hydrogen ion in solution.)
As the arterial pH goes up slightly above normal during hyperventilation, pH and CO2 sensors in the body sense this condition and signal the pH control center in the brain. It in turn, signals the arterioles and capillaries throughout the body to constrict, the heart to beat slower and the lungs to slow the rate of respiration... It does all this to slow the loss of CO2 from the lungs and allow it to build back up into the normal reference range...
Soooo... by intentionally hyperventilating we are biasing the body's homeostatic process that controls pH to stimulate vasoconstriction. When you combine hyperventilation with oxygen therapy... you get a double or triple bang for the buck. Oxygen therapy becomes more effective... and the abort times are three to four times shorter than oxygen therapy at a flow rate of 15 liters/minute...
The kidneys provide the second and slower overlapping method of controlling pH by withholding or passing hydrogen ions from the blood into the urine... This is also why adding lemonade or another fruit juice to the calcium citrate helps prevent cluster headaches... This combination forms a chemical buffer (absorbs hydrogen ions)...
Likewise, drinking a baking soda tonic made from a half teaspoon of baking soda in a half glass of water helps to prevent cluster headaches because it's an ant-acid so neutralizes a low systemic pH (too much acid).
With these examples of homeostasis in mind, we can talk about calcium homeostasis... The following diagrams illustrate the major players and flow:
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I've attached a paper that goes into far more detail on calcium homeostasis and vitamin D3...
Calcium is the fifth-most-abundant element in the earth's crust and oceans... Not surprisingly, calcium is also the fifth-most-abundant element by mass in the human body.
99% of the calcium in our bodies is located in the bones and teeth. The remaining 1% is divided between body cells and blood serum/plasma.
The total calcium serum concentration is tightly controlled by calcium homeostasis between 2.2 and 2.6 mmol/liter. Above or blow this normal reference range and we've got big problems... Nerves don't work properly nor do a lot of other biological processes that sustain life.
The following chart developed by Dr. Robert Heaney, MD, illustrates the changes in total serum calcium concentrations before and after ~130 days of treatments with either 7,000 or 12,000 IU/day vitamin D3.
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As you can see, the total serum concentration of calcium stayed within the normal reference range. No supplemental calcium was used in this study.
As calcium homeostasis is an "open" system where there's an inflow and outflow of calcium, we need to maintain a calcium intake from all sources for adults at 1000 mg/day in order to maintain bone mineral density (healthy bones).
Under normal conditions with an ample dietary intake of calcium, calcium homeostasis maintains serum calcium ion concentrations by pulling calcium primarily from the gut. It does this by using the final vitamin D3 metabolite and active hormone, 1,25(OH)2D3, (calcitriol) that was metabolized in the kidneys from 25(OH)D.
Calcium homeostasis is like the Honey Badger... It doesn't give a crap about bee stings or cobra bites as long as it gets the honey and snake meat.
Similarly, calcium homeostasis could care less about maintaining bone mineral density. If there's insufficient intake of dietary and or supplemental calcium in the gut, it will use the same active hormonal form of vitamin D3, 1,25(OH)2D3, to pull calcium from the bones in order to maintain the proper total serum concentration of calcium.
So in answer to your question... No. Supplemental calcium isn't necessary when using the anti-inflammatory regimen to prevent cluster headaches... as long as your dietary intake of calcium is around 1000 mg/day.
Even if you had no calcium intake from any source, calcium homeostasis would maintain your total serum calcium concentration within the normal reference range... until the loss of bone mineral density resulted in bone fractures...
It's interesting to note that if your total serum calcium concentration rises to and above the upper limit of the normal reference range, the parathyroids slow production of PTH (parathyroid hormone), the kidneys react to the lower PTH by slowing the metabolism of 25(OH)D into 1,25(OH)2D3 and the thyroid increases production of calcitonin...
This combination stops resorption of calcium from the bones and absorption of calcium from the gut until total serum concentration of calcium drops back into the normal reference range.
Sooo... if you're taking the anti-inflammatory regimen with 10,000 IU/day or more vitamin D3... I would look at the use of supplemental calcium ~500 mg/day as a prudent insurance policy to prevent BMD loss... At less than 5 cents a day... it's a good deal.
Finally... if the discussion of thyroid, parathyroid, calcitonin, PTH and metabolizing 25(OH)D into 1,25(OH)2D3 has the clue bird hovering close over your head and you've connected a few of these dots... you can see that problems with one or more of these organs or hormones can perturbate calcium homeostasis or cause it to cease functioning completely... It can also make the anti-inflammatory regimen ineffective in preventing cluster headache.
If you've been taking the anti-inflammatory regimen for over a month without a favorable response and you think you may have one or more of the above comorbidities... you need to see a competent endocrinologist... not a neurologist.
Take care and hope this answered your question.
V/R, Batch