Vitamin D status after a high dose of cholecalciferol in healthy and burn subjects

Background: Burn patients are at risk of vitamin D (VD) deficiency and may benefit from its
pleiotropic effects as soon as acute phase. Aim of this observational study was to assess
effects of a cholecalciferol (VD3) bolus on VD status in adult burn patients (Group B, GB) after
admission, compared to healthy subjects (Group H, GH).
Methods: Both groups received an oral dose of 100,000 IU VD3. Blood samples were collected
before (D0) and 7 days (D7) after bolus to measure 250H-D, 1,25(OH)2-D, parathyroid
hormone (PTH) and fibroblast growth factor 23 (FGF23). Albumin (ALB) and VD binding
protein (DBP) were measured and used to calculate free 25OH-D level. Data were expressed
as median (min–max) or proportions.
Results: A total of 49 subjects were included: 29 in GH and 20 in GB. At D0, prevalence of VD
deficiency was higher in GB: 25OH-D was 21.5 (10.1–46.3) ng/ml in GH vs 11 (1.8–31.4) ng/ml in
GB. DBP and ALB were lower in GB. At D7, DBP was stable in both groups while ALB decreased
in GB. 25OH-D increased by 66.6 (13.5–260.3)% in GH. In GB, changes in 25OH-D extended
from 36.7% to 333.3% with a median increase of 33.1%. Similar changes were observed in
each group for free 25OH-D. High FGF23 levels were observed in GB.
Conclusions: This study highlighted the differences in VD status and in response to a high
dose VD3 in burn patients when compared to healthy patients. Pitfalls in VD status
assessment are numerous during acute burn care: 25OH-D measurement needs cautious
interpretation and interest of free 25OH-D is still questionable. They should not prevent
burn patients to receive VD supplements during acute care. Higher doses than general
recommendations should probably be considered.