Subject: It takes a real dose of vitamin D to make a difference and its not 600 IU.
Author: trigonometry1972@gmail.com |Date: 4 Jul
Vitamin D intake to attain a desired serum
25-hydroxyvitamin D concentration 1,2,3
John F Aloia, Manish Patel, Rhett DiMaano,
Melissa Li-Ng, Sonia A Talwar, Mageda Mikhail,
Simcha Pollack and James K Yeh
The Bone Mineral Research Center,
Winthrop University Hospital,
Mineola, NY
Background: Indirect evidence suggests that optimal
vitamin D status is achieved with a serum 25-hydroxyvitamin
D [25(OH)D] concentration >75 nmol/L.
Objective: We aimed to determine the intake of vitamin D3
needed to raise serum 25(OH)D to >75 nmol/L.
Design: The design was a 6-mo, prospective, randomized,
double-blinded, double-dummy, placebo-controlled study of
vitamin D3 supplementation. Serum 25(OH)D was measured by
radioimmunoassay. Vitamin D3 intake was adjusted every
2 mo by use of an algorithm based on serum 25(OH)D concentration.
Results: A total of 138 subjects entered the study.
After 2 dose adjustments, almost all active subjects
attained concentrations of 25(OH)D >75 nmol/L, and
no subjects exceeded 220 nmol/L. The mean (±SD) slope
at 9 wk [defined as 25(OH)D change/baseline dose] was
0.66 ± 0.35 (nmol/L)/(µg/d) and did not differ
statistically between blacks and whites. The mean daily
dose was 86 µg (3440 IU). The use of computer simulations
to obtain the most participants within the range of
75–220 nmol/L predicted an optimal daily dose of
115 µg/d (4600 IU). No hypercalcemia or hypercalciuria
was observed.
Conclusions: Determination of the intake required to
attain serum 25(OH)D concentrations >75 nmol/L must
consider the wide variability in the dose-response
curve and basal 25(OH)D concentrations. Projection
of the dose-response curves observed in this
convenience sample onto the population of the
third National Health and Nutrition Examination
Survey suggests a dose of 95 µg/d (3800 IU) for
those above a 25(OH)D threshold of 55 nmol/L and
a dose of 125 µg/d (5000 IU) for those below that
threshold.
