This has to do with the regulation
of calcium absorption in puppies — they can not protect themselves from absorbing excess dietary calcium like adult dog's body can [16, 17].
Ancient DNA from early Iberian farmers shows that the wideheld evolutionary
hypothesis of calcium absorption was not the only reason Europeans evolved milk tolerance.
Oxalic acid, also known as oxalate, is the most potent
inhibitor of calcium absorption and is found at high concentrations in spinach and rhubarb and somewhat lower concentrations in sweet potatoes and dried beans.
Both in vitro and in vivo, dex significantly increases vitamin D receptor (VDR) ligand binding in the tumor while decreasing binding in intestinal mucosa, the
site of calcium absorption.
This can in turn lead to the development of conditions like Anemia (lack of Iron absorption) and and Osteoporosis (
lack of Calcium absorption).
The
efficiency of calcium absorption in the small intestine increases with higher levels of serum 25 (OH) D, reaching a plateau at 32 ng / mL.24 Some studies suggest that the lower end of the IOM reference range for 25 (OH) D, 20 ng / mL, may not optimize calcium absorption, and that levels of at least 32 ng / mL may be required.25
Estrogen is involved in the
process of calcium absorption into the bones; thus, due to the drop in estrogen levels, women will experience an accelerated reduction in bone density from perimenopause onwards.
Ancient DNA from early Iberian farmers shows that the widely held evolutionary
hypothesis of calcium absorption was not the only reason Europeans evolved milk tolerance.