Vitamin D levels of anaesthetists in the department of anaesthesiology at the University of the Witwatersrand
Date
2016
Authors
Kelly, Eugene Hamerton
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Abstract
Background and Objective
There has been a recent resurgence of interest in vitamin D and its far-reaching
effects in physiology and pathophysiology. Theatre personnel, and all indoor
workers, should be cognisant of vitamin D deficiency as a real occupational hazard.
Vitamin D deficiency is a global problem that has been studied extensively in colder
climates and even been found in warmer climates. No research was identified
among medical personnel in South Africa.
The primary objective of this study was to describe serum 25-hydroxyvitamin D
(25(OH)D) levels of anaesthetists.
The secondary objective was to describe and compare factors influencing vitamin D
levels in anaesthetists who are vitamin D insufficient to those who are not. These
factors included: ethnicity, gender, body mass index (BMI), multivitamin use, calcium
or vitamin D supplementation, sun exposure, vitamin D intake from diet alone,
vitamin D intake from diet and supplementation and calcium intake (dairy).
Methods
Data was collected over a period of one month, in winter (mid-July to mid-August
2013).
On the morning of sample collection anaesthetists agreeing to participate signed the
informed consent (Appendix 2), prior to enrolment in the study. The anaesthetists
then completed the questionnaire (Appendix 5). The following data was obtained
from the questionnaire: age, gender, ethnic group, dietary supplementation, sun
exposure, sunscreen use, BMI and diet.
Each participant had 5 ml of blood collected in a standardised manner into a purple
top ethylenediaminetetraacetic acid blood specimen tube. The processing of
samples was done by qualified laboratory personnel using standard chemical
pathology equipment and procedures. High Performance Liquid Chromatography
was performed to determine 25(OH)D levels using a Shimadzu® Nexera X2 Ultra
performance liquid chromatography system with a photodiode array detector
(Shimadzu®, Japan).
Results
The median 25(OH)D was 43.8 nmol/l (IQR 26-76), with 51 of 89 (57.30 %)
anaesthetists being vitamin D insufficient.
There was a statistically significant association between ethnicity and vitamin D
status (p<0.001). Twenty-one (80.77 %) Indian anaesthetists and 14 (70.00 %) black
anaesthetists were vitamin D insufficient, as compared to only 10 (28.57%) white
anaesthetists.
There was no significant association between the other secondary objectives-gender
(p=0.60), sun exposure (p = 0.93), vitamin D intake from diet alone (p= 0.07), vitamin
D intake from diet and supplementation (p=0.05) and calcium intake (p=0.55) and
vitamin D status.
There was no significant difference between BMI and vitamin D status. When a
comparison was made between the two groups of BMI <25 and BMI ≥25, using a
Mann-Whitney test the two-tailed P value was 0.6791. There was a significant
association between multivitamin use (p=0.01) and vitamin D status.
Conclusion
Vitamin D should no longer be a forgotten vitamin. The insufficient vitamin D levels of
anaesthetist in this study, puts them at risk for pathology far beyond bone health.
Adequate vitamin D levels should be seen as essential, rather than optional, even in
“sunny” climates.
Description
A research report submitted to the Faculty of Health Sciences,
University of the Witwatersrand, Johannesburg, in partial
fulfilment of the requirements for the degree
of
Master of Medicine in the branch of Anaesthesiology