Hypochlorhydria increases with age in frequency. It has NO effect on heme iron uptake. The motility of the colon decreases with age, causing an increase in constipation. As we age, there are metabolic changes in our cells. Our cardiovascular system changes as we age, too.
Blood vessels get stiffer with age.
It becomes more difficult to handle protein, wastes and electrolytes. This leads to kidney diseases, as well. Hence, this leads to structural AND functional changes. As our age increases, we exhibit decreased creatinine excretion. Decreased bone density as we age, causes osteoporosis.