How Long Does Calcium Stay High Enough In The Blood Before You Need A "refill"?

[mayweatherking]

So prolactin will go up if calcium is not high enough, we know this. With blood sugar, we have some obvious symptoms like hunger or other feelings when it starts getting low, but calcium, these triggers are not there. I know magnesium stays for up to 2 weeks with proper thyroid.

What about calcium? If I drink 16oz of milk, which would be about 500mg of calcium, how long does this calcium "sustain" the requirements to satisfy parathyroid hormone, and when would be ideal to drink another 16oz of milk to refill this?

Do you know what I'm saying?

The reason I ask this is because, what if you wake up in the morning and eat eggs and orange juice and coffee and no calcium. Are you doing yourself a disservice by not having calcium with every meal, you are increasing that PTH because youve gone too long?

 

[ecstatichamster]

I've wondered the same thing.

I think it has more to do with phosphorus intake as phosphorus intake is usually high enough to make the kidneys excrete it pretty much non-stop. Meat, dairy, grains, all have a lot of phosphorus in excess of the body's needs. Phosphate is excreted out the urine, so the kidneys are often maxed out trying to get rid of high phosphorus. There is a limit to their speed of excretion.

That's why I think having calcium at least once a day is good. The question is, is it good to take some calcium with every meal?

Right?

This study is interesting because it says that PTH has an effect that is bad when it is continuous. When it's intermittent, it isn't bad.

http://www.sciencedirect.com/science/article/pii/S8756328203002023

Parathyroid hormone (PTH)(1-34), given once daily, increases bone mass in a variety of animal models and humans with osteoporosis. However, continuous PTH infusion has been shown to cause bone loss. ...

The pharmacokinetic profiles suggest that the anabolic or catabolic response of bone to PTH(1-34) is determined primarily by the length of time each day that serum concentrations of PTH(1-34) remain above baseline levels of endogenous PTH and only secondarily by the Cmax [maximum serum concentration at some moment] or AUC [area under the curve] of PTH(1-34) achieved.

So, if you take calcium ONCE per day, you may have an extended effect on PTH for the entire day. Enough to suppress PTH for hours, and that would be enough to prevent damage from too much PTH.

Calcium is excreted through feces mostly, while phosphorus is excreted via the kidneys. So I think a single dose of calcium is probably going to last for some hours to balance out excess phosphorus.