Effects of Fluorescent Lighting Versus Sunlight Exposure on Calcium, Magnesium, Vitamin D, and Feather Destructive Behavior in Hispaniolan Amazon Parrots (Amazona ventralis)

Ethnic-Based Assessment of Vitamin D and Magnesium Status in the Kingdom of Bahrain

BACKGROUND

Vitamin D deficiency is a major global health problem. Most previous studies focused attention on the significant role of sunlight exposure in the homeostasis of vitamin D and calcium blood levels. Magnesium is pivotal in the proper functioning of vitamin D, and the physiologic functions of different organs require a balanced vitamin D and magnesium status. The relationship between sunlight exposure and blood levels of vitamin D and magnesium has often been overlooked. The aim of this study was to evaluate vitamin D and magnesium status based on sunlight exposure and ethnicity in Bahraini and expatriate workers.

METHODS

A cross-sectional study was conducted between October 2018 and September 2019. One hundred and seventy-four subjects participated in this study were subdivided based on their ethnicity and work environment-dependent exposure to sunlight into four groups: (1) Bahraini exposed (n=94), (2) Bahraini non-exposed (n=25), (3) expatriate exposed (n=31), and (4) expatriate non-exposed (n=24). Blood levels of vitamin D and magnesium were evaluated for all the participants.

RESULTS

 Independent of ethnicity, vitamin D levels were insignificantly different among the studied groups and were all below the normal reference range. Yet, there was still a sunlight-dependent increase in vitamin D level that could be seen only in Bahraini workers. Magnesium levels were significantly higher in expatriates when compared to Bahraini workers. Sunlight-exposed expatriates had significantly higher magnesium levels than their Bahraini counterparts, while there was no significant difference between both ethnicities in the non-exposed groups.

CONCLUSION

Country- and ethnic-specific definitions for vitamin D status and sunlight exposure are recommended. The assessment of magnesium status is pivotal in the overall assessment of vitamin D status.

Plasma Vitamin D (25-Hydroxyvitamin D) Levels in Hispaniolan Amazon Parrots (Amazona ventralis) Housed Indoors Over Time

Vitamin D is a hormone that can be ingested or synthesized in the body when skin is exposed to ultraviolet radiation (UV), typically from sunlight. In captivity, birds with no sunlight exposure may develop vitamin D deficiencies that may contribute to hypocalcemic conditions, even when fed a diet supplemented with vitamin D. An initial pilot study with Hispaniolan Amazon parrots (Amazona ventralis) conducted approximately 18 mo prior indicated there were significant differences in the 25-hydroxyvitamin D (vit D) plasma levels between the resident parrots (indoor-only housing) and a new group of historically outdoor-housed parrots (new parrots) 5 days after the arrival of the latter at our institution. The goals of this study were to determine if vit D, ionized calcium (Ca²⁺), and ionized magnesium (Mg²⁺) levels changed from baseline values (taken 18 mo prior) in the new birds as well as to compare those values to those of the resident birds over time. The treatment was a change in husbandry for the new parrots (no UV exposure and diet as provided for the resident parrots). To accomplish this, the authors compared vit D levels in the same two groups of birds that were fed the same vit D-fortified diet and given no access to natural or artificial UV light exposure for 18 mo. The resident parrots (N = 9) had been housed indoors for approximately 20 yr with no exposure to natural or supplemented UV light. The second group of birds (new parrots; N = 8) had been housed outdoors prior to the initiation of the pilot study in 2016 and were fed a similar-but not identical-diet prior to their arrival. Plasma samples were sent to the Michigan State University Diagnostic Center for Population and Animal Health for analysis. Test results demonstrated differences between the two groups of parrots, largely attributed to the decrease in vit D plasma levels in the new parrots over time to values equivalent to those measured in the resident birds. Differences were seen in plasma Ca²⁺, while no differences were demonstrated relative to Mg²⁺. We discuss these findings and suggest that plasma vit D levels decrease in the absence of UV light, even when animals are maintained on a vit D-fortified and balanced diet.

Medical Causes of Feather Damaging Behavior

Feather damaging behavior (FDB), also referred to as feather picking, feather plucking, or pterotillomania, is one of the most common and frustrating clinical presentations in captive psittacines. The clinical approach to identify underlying medical conditions associated with FDB is reviewed. Primary feather or skin diseases as well as systemic diseases may lead to this syndrome. This article focuses on the medical causes of FDB documented in the current avian literature. Medical causes are presented using the VITAMIN D algorithm. Key components of the multifaceted therapeutic approach in managing FDB of medical origin are discussed.