Aim: To elicit the factors affecting the severity of Vitamin D deficiency (VDD) in an endocrine outpatient population in a district general hospital.
Methodology: A retrospective analysis of serum 25-hydroxy vitamin D levels of all patients known to an endocrine clinic between 1st January 2009 and 30th June 2011. The first vitamin D level within this period was recorded. Other biochemical markers and co-morbidities were also studied.
Results: Of the 128 patients identified, 114 patients (89%) were found to have VDD. Patients with VDD were stratified into three groups; 10 (8.7%) patients had mild VDD (2530 ng/ml), with 52 (45.6%) each for moderate (2025 ng/ml) and severe VDD (<20 ng/ml). Although 77% (98/128) of subjects were female, there was no significant correlation between gender and vitamin D levels (P=0.78). Interestingly, 18.2% (4/22) of the older group (>65-years) had a normal vitamin D compared to only 10.3% (9/87) of the younger age (3064-years) group (P<0.05). Sixty-five percent of patients had ethnic origin details available, of which 65% were Asian. Despite moderate VDD being equal in both Caucasians and Asians, the prevalence of severe VDD was far higher in Asian subjects (32/54, 59.2%) than other ethnic subgroups (P=0.08). There was no significant association between degree of VDD and calcium, ALP and phosphate levels. Subjects with moderate/severe VDD were found to have a higher than normal mean parathyroid hormone (PTH) level (P<0.05) and HbA1c levels (P>0.05). No significant association between VDD and hypertension was found as the numbers may have been too small for a definitive conclusion.
Conclusion: The severity of VDD may be influenced by ethnic origin and age. PTH was the only biochemical marker that significantly increased with severity of deficiency.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.