CONTEXT: Several trials have reported an increased risk of fractures and falls after intermittent high-dose vitamin D. Treatment with loading doses of vitamin D may increase 1,25(OH)(2) vitamin D catabolism through changes in calcium/phosphate homeostasis and fibroblast growth factor-23 (FGF-23). OBJECTIVE: The aim was to determine the effects of high-dose vitamin D on circulating concentrations of 1,25(OH)(2) vitamin D and FGF-23 in patients with osteoporosis and vitamin D insufficiency. DESIGN, SETTING, PATIENTS, AND INTERVENTION: We carried out a prospective study of 45 subjects with vitamin D deficiency/insufficiency treated with a bolus dose of 300 000 IU of vitamin D(2) im. Blood samples were obtained at baseline and 1, 2, and 3 months after treatment. OUTCOME MEASURES: Changes in 1,25(OH)(2)-vitamin D and FGF-23 were measured. RESULTS: Loading dose of vitamin D(2) increased 1,25(OH)(2)-vitamin D(2) at 3 months, with a mean [SD] of 41 [56] pmol/L at baseline and 162.3 [137.8] pmol/L at 3 months (P < .001). FGF-23 increased significantly at all time points with a peak at 3 months, with percent change from baseline (mean [SEM]) of 50% [48%] at 3 months (P < .01). There was a positive correlation between FGF-23 and serum phosphate (r = 0.36, P = .024) and calcium (r = 0.532, P < .001) and a negative correlation between total 1,25(OH)(2)-vitamin D and FGF-23 (r = -0.32, P = .036) at 3 months. CONCLUSIONS: High-dose vitamin D increases 1,25(OH)(2)-vitamin D and FGF-23 concentration. Further studies are required to determine whether adjusting vitamin D dose and frequency to minimize increases in FGF-23 may prevent the adverse outcomes associated with high-dose intermittent vitamin D supplementation.
CONTEXT: Several trials have reported an increased risk of fractures and falls after intermittent high-dose vitamin D. Treatment with loading doses of vitamin D may increase 1,25(OH)(2)vitamin D catabolism through changes in calcium/phosphate homeostasis and fibroblast growth factor-23 (FGF-23). OBJECTIVE: The aim was to determine the effects of high-dose vitamin D on circulating concentrations of 1,25(OH)(2)vitamin D and FGF-23 in patients with osteoporosis and vitamin Dinsufficiency. DESIGN, SETTING, PATIENTS, AND INTERVENTION: We carried out a prospective study of 45 subjects with vitamin Ddeficiency/insufficiency treated with a bolus dose of 300 000 IU of vitamin D(2) im. Blood samples were obtained at baseline and 1, 2, and 3 months after treatment. OUTCOME MEASURES: Changes in 1,25(OH)(2)-vitamin D and FGF-23 were measured. RESULTS: Loading dose of vitamin D(2) increased 1,25(OH)(2)-vitamin D(2) at 3 months, with a mean [SD] of 41 [56] pmol/L at baseline and 162.3 [137.8] pmol/L at 3 months (P < .001). FGF-23 increased significantly at all time points with a peak at 3 months, with percent change from baseline (mean [SEM]) of 50% [48%] at 3 months (P < .01). There was a positive correlation between FGF-23 and serum phosphate (r = 0.36, P = .024) and calcium (r = 0.532, P < .001) and a negative correlation between total 1,25(OH)(2)-vitamin D and FGF-23 (r = -0.32, P = .036) at 3 months. CONCLUSIONS: High-dose vitamin D increases 1,25(OH)(2)-vitamin D and FGF-23 concentration. Further studies are required to determine whether adjusting vitamin D dose and frequency to minimize increases in FGF-23 may prevent the adverse outcomes associated with high-dose intermittent vitamin D supplementation.
Authors: Casey M Rebholz; Morgan E Grams; Pamela L Lutsey; Andrew N Hoofnagle; Jeffrey R Misialek; Lesley A Inker; Andrew S Levey; Elizabeth Selvin; Chi-Yuan Hsu; Paul L Kimmel; Ramachandran S Vasan; John H Eckfeldt; Josef Coresh Journal: Am J Kidney Dis Date: 2015-10-23 Impact factor: 8.860
Authors: Rukshana Shroff; Helen Aitkenhead; Nikola Costa; Antonella Trivelli; Mieczyslaw Litwin; Stefano Picca; Ali Anarat; Peter Sallay; Fatih Ozaltin; Aleksandra Zurowska; Augustina Jankauskiene; Giovanni Montini; Marina Charbit; Franz Schaefer; Elke Wühl Journal: J Am Soc Nephrol Date: 2015-06-11 Impact factor: 10.121
Authors: George Griffin; Martin Hewison; Julian Hopkin; Rose Anne Kenny; Richard Quinton; Jonathan Rhodes; Sreedhar Subramanian; David Thickett Journal: Clin Med (Lond) Date: 2021-02-16 Impact factor: 2.659
Authors: Hemamalini Ketha; Tom D Thacher; Sara S Oberhelman; Philip R Fischer; Ravinder J Singh; Rajiv Kumar Journal: Bone Date: 2018-02-24 Impact factor: 4.398