A vitamin D deficiency lowers calcium absorption and can lead to which pair of conditions?

1. Calcium is absorbed through the intestines under the influence of activated vitamin D. 2. Without enough vitamin D the intestinal epithelium absorbs less calcium. 3. The body then draws on the skeleton, and calcium stores there are depleted. 4. In children whose bone is still growing this presents as rickets. 5. In adults the same depletion presents as osteomalacia. 6. Over time it also contributes to osteoporosis. 7. Reversing the two age groups inverts the real pattern, which is the trap in the second option. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 26 "Fluid, Electrolyte, and Acid-Base Balance", section Calcium_