K/DOQI recommends spending 3-6 months correcting 25-OH vitamin D deficiency prior to graduating to active vitamin D to control secondary hyperparathyroidism in CKD patients. I have been aggressively treating vitamin D deficiency in my CKD clinic for years and have found a pretty modest affect on PTH. Generally you get 20-30% reduction in PTH by correcting 25-OH D but occasionally you get a real responder.
I just saw a patient with modest stage 3 CKD. When I first saw her she had a 25-OH D of 7 and a PTH of 288. I started her on 50,000 units of ergocalciferol a week. It took 12 months but we finally corrected her vitamin D deficiency and her secondary hyperparathyroidism just melted away.
The 25-OH vitD seems very low to me. Did you asked yourself the question Why this was so low. Did the patient have a deficient diet, seen no sunlight or have a malabsorption syndrome?
I have seen many patients with 25OH in 4-10 range although not all correct to normal range, 2/3rd correction rate!
I think there is a small trial from boston stating that not every one corrects to normal range.
Why wait one entire year to correct the Deficiency. I would have treated with 100,000 units po qd for 5-10 days.
Ergoclaciferol (D2) is not as effective in humans as colicalciferol (D3). Unfortunately, the megadose vitamins that big Pharma makes are D2. Here's some research on this. Link:
Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans
Laura A. G. Armas, Bruce W. Hollis and Robert P. Heaney
http://jcem.endojournals.org/cgi/content/full/89/11/5387
Hoosierville
Awesome feedback.
Regarding the time to treat the patient. This patient had almost no appreciable renal disease outside of the SHPTH. I was not going to schedule frequent visits to monitor therapy I just put them on a safe and familiar vitamin D dose and followed up every six months. I don't think I harmed the patient with slow therapy. The one time I had a patient on 50,000 units daily (resident error) they were readmitted within 2 weeks with hypercalcemia.
Regarding the low vitamin D. We live in Detroit and see the sun once every 4 years on Henry Ford's birthday. I routinely see vitamin D levels this low. I don't think she has any other diseases leading to low vitamin D levels because she has been able to maintain a normal vitamin D status since replacement.
Regarding the inability of the K/DOQI prescribed treatment to actually correct the deficiency. Agreed.
Regarding the difference between D2 and D3, I have also seen this data but have never acted on it.