Objective
The present study was undertaken to determine if a seasonal bias was present for vitamin
D testing among Northeast Tennessee veterans, in whom vitamin D deficiency is common.
Design
Medical chart review.
Setting
VA Medical Center.
Participants
Participants were 9447 patients with initial 25(OH) vitamin D levels obtained over
a 3-year period.
Measurement
Serum 25-hydroxyvitamin D (25[OH]D) level, date of testing, patient background factors.
Results
Vitamin D testing occurred more frequently in September, October, November, and December,
whereas the lowest levels of 25(OH) vitamin D levels were found in January, February,
and March. Similar results were observed in quarterly data with the greatest number
of tests noted in the last quarter of the year, yet the lowest 25(OH) vitamin D levels
were noted in the first quarter. The average monthly 25(OH) vitamin D levels were
below 30 ng/mL throughout the year in the study population, consistent with highly
prevalent vitamin D deficiency.
Conclusion
Clinicians may have a seasonal bias, favoring testing for vitamin D status in the
latter part of the year even though the lowest vitamin D levels are observed in the
first part of the year. Although an argument could be made to check for peak 25(OH)
vitamin D levels in September and trough levels in March, the seasonal contribution
to vitamin D deficiency is overshadowed by ongoing vitamin D deficiency throughout
the year. Thus, it may be prudent to test for vitamin D deficiency in patients presenting
with fatigue, myalgias, and arthralgias regardless of the season of presentation.
Keywords
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Article info
Publication history
Published online: January 13, 2010
Identification
Copyright
Published by Elsevier Inc.
