Effect of the Addition of an Ultraviolet B Light Bulb for 6 Months to the Enclosure of Client-Owned Cockatiels (Nymphicus hollandicus) on Serum 25-Hydroxyvitamin D Concentrations

Background

The objective of this study was to determine the effects of ultraviolet B (UVB) radiation on the serum concentration of 25-hydroxyvitamin D [25(OH)D] in pet cockatiels (Nymphicus hollandicus) living in their home environments.

Methods

Thirty client-owned cockatiels were allocated to an intervention group, consisting of exposure to a commercial coil fluorescent bulb, or a control group, with no exposure to supplemental lighting. Blood samples were collected at baseline (Day 0) and 6 months after simple randomization for measurement of 25(OH)D (Day 180). A linear mixed model was used to determine if serum 25(OH)D concentrations were influenced by time, group, age, or sex.

Results

At baseline, median 25(OH)D concentration for the whole study population was 13 nmol/L (range, 0.0–15.0 nmol/L). At the end of the study, median 25(OH)D concentration for the whole study population was 6.5 nmol/L (0.0–15.0 nmol/L), for the control group was 3 nmol/L (0.0–8.0 nmol/L) and for the UVB group was 7.5 nmol/L (6.0–11.0 nmol/L). There was a statistically significant 50% reduction in 25(OH)D concentrations from the baseline to the final sampling period for the overall population, but no differences by group, age, or sex.

Conclusion and clinical relevance

The addition of a UVB bulb for 6 months to the enclosures of cockatiels did not increase their serum 25(OH)D concentrations. There was an unexplained decrease in both groups when comparing Day 0 to the Day 180 sampling period. The 50% attenuation in the UVB lighting group, although not statistically significant, may be clinically relevant and deserves further investigation.