Severe vitamin D deficiency is common in critically ill patients at a high northern latitude.
BACKGROUND
Critically ill patients at southern latitudes have been shown to have low vitamin D levels that were associated with prolonged hospital stay. To our knowledge no studies have been conducted on vitamin D status amongst critically ill patients at high northern latitudes. Despite the Icelandic population traditionally taking vitamin D supplements, we hypothesized that the majority of critically ill patients in Reykjavik, Iceland have low vitamin D levels.


METHODS
This was a prospective observational study on 122 patients admitted to Landspitali University Hospital intensive care unit. Serum vitamin D (25(OH)D) was measured in all patients on two occasions (first and second day). The prevalence of vitamin D deficiency and its effect on hospital stay was calculated.


RESULTS
Only 9% of patients had vitamin D levels recommended for good health (>75 nmol/l) and 69% were deficient (25(OH)D < 50 nmol/l). The average difference between the first and second vitamin D samples was 2.8 nmol/l. Forty-three percentage of the severely vitamin D deficient stayed in the ICU for more than 4 days compared to 19% of patients with better status (P = 0.196).


CONCLUSIONS
Vitamin D deficiency is very common in critically ill patients at high northern latitudes and patients with severely deficient vitamin D levels had trend towards longer intensive care unit stay. Furthermore, 43% of the patients had vitamin D levels under 25 nmol/l that is associated with osteomalacia. It appears that a single vitamin D measurement gives a reasonable clue about the vitamin D status in critically ill patients.
Department of Anaesthesia and Intensive Care Medicine, Department of Anaesthesia and Intensive Care Medicine, Landspitali University Hospital, Reykjavik, Iceland.|Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
R B
RB
Kvaran
Department of Anaesthesia, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA, USA.
M I
MI
Sigurdsson
Department of Anaesthesia and Intensive Care Medicine, Department of Anaesthesia and Intensive Care Medicine, Landspitali University Hospital, Reykjavik, Iceland.
S J
SJ
Skarphedinsdottir
Department of Anaesthesia and Intensive Care Medicine, Department of Anaesthesia and Intensive Care Medicine, Landspitali University Hospital, Reykjavik, Iceland.|Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
G H
GH
Sigurdsson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
D014807:Vitamin D; C104450:25-hydroxyvitamin D