To test their hypotheses, the scientists bottle-fed 12 piglets a calcium-rich diet and another 12 piglets a calcium-deficient diet during the first 18 days of life. Throughout the study, blood samples were drawn frequently from the piglets, and they were weighed daily. At the end of the study, the researchers collected samples from the animals' bone marrow, livers, kidneys, and small intestines. They also tested their hind legs for bone density and strength.
Their results were both surprising and intriguing. For instance, there were no differences between groups in terms of blood markers of calcium status and growth. These data support the previously suggested concept that, unlike what happens in adults, calcium absorption in newborns is not dependent on vitamin D. They also documented marked differences in bone density and strength such that the calcium-deficient piglets were compromised. When they looked at the bone marrow tissue which contains all the material (known as mesenchymal stem cells) that will eventually become bone-forming cells, they discovered that many of the calcium-deficient piglets' cells appeared to have already been programmed to become fat cells instead of bone-forming osteoblast cells. Fewer osteoblasts in early life may translate to a diminished ability for bones to grow and repair themselves throughout the remainder of life. Thus, it appeared as if calcium deficiency had predisposed the animals to having bones that contained more fat and less mineral.
Dr. Stahl concluded that "While the importance of calcium nutrition throughout childhood and adolescence is well recognized, our work suggests that calcium nutrition of the
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Federation of American Societies for Experimental Biology