Continuing the discussion from (Soylent + Whey) and/or (other stuff) == Nausea? (1.5):
Calcium carbonate is a natural form of calcium. What would you suggest replacing it with?
Low bioavailability doesn’t matter if nutritional needs are met. Even if calcium carbonate has lower bioavailability than an alternative (e.g., calcium citrate), it also contains a high % of elemental calcium (40% in calcium carbonate vs. 21% in calcium citrate). It may be more efficient if you take that into account.
I found this interesting: Calcium bioavailability and absorption.
To cover an obligatory loss of 250 mg/day, the 800 mg/day RDA for adults assumes an average absorption of 30%.
I didn’t read the whole thing, but I skimmed it. Some tidbits:
- Measuring the absorption accurately is a huge challenge.
- Increased fiber intake can significantly reduce calcium absorption.
- The body actually adapts to absorb calcium more efficiently when calcium-deficient, although this is not a reason to neglect calcium intake.
- Calcitriol increases calcium absorption.
Soylent contains ergocalciferol (vitamin D2), which metabolizes to calcitriol. Exposing skin to sunlight should lead to increased calcium absorption as well; this is a great reason to visit a nude beach.