You are planning to start a 72-year-old man who has chronic renal failure and secondary hyperparathyroidism on 1,25-OH vitamin D supplementation.
Which of the following correctly represents an action of 1,25-OH vitamin D supplementation?
Decreased calcium reabsorption in the kidney
Decreased IL6 production
Decreased intestinal reabsorption of calcium
Decreased mobilisation of calcium from bone
Decreased muscle strength
Explanation:
As well as its documented effects on the kidney and bone, vitamin D is recognised to modulate cytokine production and may have a role in the treatment of inflammatory disorders in the future. One example is decreased production of IL6 in response to vitamin D supplementation.
With respect to calcium metabolism, the actions of vitamin D are to increase serum calcium. This includes increased intestinal absorption of calcium, increased mobilisation of calcium from bone, and increased calcium reabsorption from the kidney.
Vitamin D deficiency, rather than supplementation, is thought to contribute to decreased muscle strength.