Vitamin D and bone health in adults with cystic fibrosis.
BACKGROUND
Cystic fibrosis (CF) patients have chronic pancreatic insufficiency leading to malabsorption of fat-soluble vitamins, including vitamin D which can contribute to poor skeletal health and respiratory function.


OBJECTIVE
This study evaluated the prevalence of vitamin D insufficiency and its impact on bone and respiratory health in adults with CF.


METHODS
This was a retrospective study in which data were collected from medical records over a 2-year period. Data included patient demographics, lung function, biochemical data, bone mineral densities, X-rays and ascertainment of use of vitamin supplements. Data were collected from medical records at a single accredited CF Center. Serum 25-hydroxyvitamin D [25(OH)D] levels and bone mineral density studies were also collected.


METHODS
A total of 185 adults with CF were identified with a mean age of 29 +/- 9 years.


RESULTS
The prevalence of vitamin D insufficiency [25(OH)D < 75 nmol/l] was 76%. Mean serum 25(OH)D concentrations were 58.8 +/- 30 nmol/l. Use of specific vitamin D supplementation was protective against vitamin D insufficiency whereas use of multivitamins was not. There was a small, but significant, positive association between serum 25(OH)D and FEV(1) per cent predicted after controlling for age, gender, BMI and race (R(2) = 0.30, P < 0.001). A high prevalence (27%) of vertebral fractures was detected on lateral chest X-ray.


CONCLUSIONS
The prevalence of vitamin D insufficiency and poor skeletal health is high in the US CF population. Vitamin D status appears to be positively associated with lung function. Prospective studies to examine the impact of correction of vitamin D insufficiency on skeletal and lung health in adult CF are warranted.
Wolfenden
Linda L
LL
Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Emory University School of Medicine, Emory University Cystic Fibrosis Center, Atlanta, GA 30322, USA.
Judd
Suzanne E
SE
Shah
Reshma
R
Sanyal
Rupan
R
Ziegler
Thomas R
TR
Tangpricha
Vin
V
D000328:Adult; D015519:Bone Density; D001847:Bone Diseases / Q000097:blood / Q000453:epidemiology*; D001842:Bone and Bones / Q000502:physiology*; D003550:Cystic Fibrosis / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006262:Health; D006801:Humans; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D012621:Seasons; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000150:complications / Q000453:epidemiology*; D055815:Young Adult
D014807:Vitamin D