High-dose oral vitamin D3 supplementation in the elderly.
CONCLUSIONS
Daily dosing with vitamin D often fails to achieve optimal outcomes, and it is uncertain what the target level of 25-hydroxyvitamin D should be. This study found that large loading doses of vitamin D(3) rapidly and safely normalize 25OHD levels, and that monthly dosing is similarly effective after 3-5 months. With baseline 25OHD > 50 nmol/L, vitamin D supplementation does not reduce PTH levels.


BACKGROUND
There is concern that vitamin D supplementation doses are frequently inadequate, and that compliance with daily medication is likely to be suboptimal.


METHODS
This randomized double-blind trial compares responses to three high-dose vitamin D(3) regimens and estimates optimal 25-hydroxyvitamin D (25OHD) levels, from changes in parathyroid hormone (PTH), and procollagen type I amino-terminal propeptide (P1NP) in relation to baseline 25OHD. Sixty-three elderly participants were randomized to three regimens of vitamin D supplementation: a 500,000-IU loading dose; the loading dose plus 50,000 IU/month; or 50,000 IU/month.


RESULTS
The Loading and Loading + Monthly groups showed increases in 25OHD of 58 +/- 28 nmol/L from baseline to 1 month. Thereafter, levels gradually declined to plateaus of 69 +/- 5 nmol/L and 91 +/- 4 nmol/l, respectively. In the Monthly group, 25OHD reached a plateau of ~80 +/- 20 nmol/L at 3-5 months. There were no changes in serum calcium concentrations. PTH and P1NP were only suppressed by vitamin D treatment in those with baseline 25OHD levels <50 and <30 nmol/L, respectively.


CONCLUSIONS
Large loading doses of vitamin D(3) rapidly and safely normalize 25OHD levels in the frail elderly. Monthly dosing is similarly effective and safe, but takes 3-5 months for plateau 25OHD levels to be reached.
Bacon
C J
CJ
Department of Medicine, University of Auckland, Auckland, New Zealand.
Gamble
G D
GD
Horne
A M
AM
Scott
M A
MA
Reid
I R
IR
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D002762:Cholecalciferol / Q000008:administration & dosage*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D016330:Frail Elderly; D018737:Hand Strength; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014815:Vitamins / Q000008:administration & dosage*
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D011347:Procollagen; D014815:Vitamins; C047202:procollagen Type I N-terminal peptide; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D