1. The Physiology and Pathophysiology of Vitamin D
MAURICE AUDRAN, M.D. 
Mayo Clinic Proceedings 
Volume 60, Issue 12, Pages (December 1985)
DOI: /S (12)
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

2. Fig. 1 Formation of vitamin D3 in the skin. UV = ultraviolet.
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

3. Fig. 2 Formation of 25-hydroxyvitamin D, in the liver.
(From Kumar R: Metabolism of vitamin D. In Clinical Medicine. Vol 8. Chap 10. Edited by JA Spittell Jr. Philadelphia, Harper & Row, Publishers, By permission.)
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

4. Fig. 3
Formation of 1,25-dihydroxyvitamin D3 in the mitochondria of cells in the proximal tubule of the kidney. Ca = calcium; Nor = normal; Pi = inorganic phosphate.
(From Kumar R: Metabolism of vitamin D. In Clinical Medicine. Vol 8. Chap 10. Edited by JA Spittell Jr. Philadelphia, Harper & Row, Publishers, By permission.)
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

5. Fig. 4
Physiologic defenses in hypocalcemia (left) and hypercalcemia (right). Ca = calcium; CT = calcitonin; 1,25-(OH)2D3 = 1,25-dihydroxyvitamin D3; 25(OH)D3 = 25-hydroxyvitamin D3; PTH = parathyroid hormone.
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

6. Fig. 5
Physiologic defenses in hypophosphatemia (left) and hyperphosphatemia (right). Ca = calcium; 25(OH)D3 = 25-hydroxyvitamin D3; Pi = inorganic phosphate; PTH = parathyroid hormone.
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Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

7. Fig. 6
Mechanism of action of 1,25dihydroxyvitamin D [1,25(OH)2D] in the intestinal cell. Ca = calcium; mRNA = messenger ribonucleic acid; Na = sodium.
(From Kumar R: Metabolism of vitamin D. In Clinical Medicine. Vol 8. Chap 10. Edited by JA Spittell Jr. Philadelphia, Harper & Row, Publishers, By permission.)
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions

8. Fig. 7 Metabolism of 1,25-dihydroxyvitamin D3.
(From Kumar R.2 By permission of the American Physiological Society.)
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1985 Mayo Foundation for Medical Education and Research Terms and Conditions