HPLC and ICP-MS in the Measurement of Vitamins and Minerals in Pet Grey Parrots

While grey parrots (Psittacus erithacus) are commonly kept as pet birds around the world, very little is known about their plasma vitamin and mineral concentrations. Researchers, therefore, set out to establish reference intervals for vitamins A, D, and E and various minerals (calcium, cobalt, copper, iron, iodine, potassium, magnesium, manganese, molybdenum, sodium, inorganic phosphorus, selenium, and zinc) in the plasma of 88 adult pet grey parrots in Germany. The samples were collected during routine health checks and analyzed using a point-of-care device, an autoanalyzer, inductively coupled plasma mass spectrometry (ICP-MS), and high performance liquid chromatography (HPLC). A paper based on this research was published in the Journal of Avian Medicine and Surgery.¹

How Do Diet and Sunlight Affect Vitamin D, A, and E Levels in Grey Parrots, and Why Does It Matter for Their Care?

The birds involved in the study (47 males, 38 females, and 3 of unknown sex) ranged in age from 6 months to 57 years old, averaging around 20 years. Housing-wise, 46 lived indoors only, 38 had outdoor aviary access with sunlight, and 4 were unknown. Regarding diet, 43 ate just fruit, veggies, and seeds, 38 also got pellets and/or supplements, and 7 were unknown. Splitting by housing, the outdoor birds were roughly even between pellets/supplements (22) and plain diets (16), while indoor birds leaned more toward plain diets (25) over pellets/supplements (16).¹

The average vitamin A level of the parrots tested (466.70 µg/L) closely matched what's been seen in US parrots (471 µg/L) in previous research.² Vitamin E was different; the US study came in 69% lower (13.05 vs. our 41.89 mg/L). For vitamin D, a study of grey parrots fed only seeds (no supplements) for a year found levels 63% higher than ours (46.68 ± 50.76 vs. our 17.35 ± 14.78 ng/mL). Both studies saw a wide spread of values, likely because UVB exposure varied so much among the birds. Our results confirm that sunlight boosts plasma vitamin D in grey parrots, but diet matters too

Other studies back this up with mixed nuances: grey parrots under artificial UVB lighting for a year showed higher vitamin D and calcium if fed seeds, while pellet-fed birds had higher calcium but no real vitamin D change.³ In this study, sunlight-exposed birds had higher vitamin D but no real difference in calcium, phosphorus, or magnesium. Pionus parrots showed no sunlight effect on calcium or vitamin D at all,³ while Hispaniolan Amazon parrots' vitamin D dropped without sunlight.⁴

“The results,” write the authors of the paper,¹ “show that these factors play important roles and should be considered in the husbandry and management of these parrots, as well as in the interpretation of blood results. The established reference intervals should help to improve the medical care of grey parrots and better monitor and optimize feeding and husbandry.”

What Are the Weaknesses of this Study, and Do They Undermine its Conclusions?

The researchers admit that their study had a few drawbacks worth keeping in mind. The blood samples came from pet parrots belonging to different owners, who fed their birds different diets and used different supplement brands. Because the actual diets were not analyzed in detail, they could not say for certain how specific foods or supplements affected the results. The birds also were not housed under the same conditions, and no measurements regarding how much UV light they got or for how long took place. The study also ran for a year and a half, covering multiple seasons, but the sample size was too small to account for seasonal changes, even though the birds' physiology could shift with the seasons and affect the numbers. Another point to consider is that some of the parrots had a fungal infection of the air sacs, which seemed to throw off their vitamin E and selenium levels (both of which act as antioxidants in the body).¹

Even with these caveats, however, the researchers state that their study succeeds in laying out solid reference ranges for several vitamins and minerals in grey parrots, as well as showing that diet and sunlight exposure do influence some of these levels. Going forward, more research is needed to figure out how other factors, like season, might play a role as well.¹

References

1. Leineweber, C.; Reese, L.; Britsch, G. et al. Marschang, R. E. Blood Plasma Vitamin and Mineral Concentrations in Pet Grey Parrots (Psittacus erithacus) in Germany. J Avian Med Surg. 2026, 40 (2), 121-128. DOI: 10.1647/AVIANMS-D-25-00022
2. Torregrossa, A. M.; Puschner, B.; Tell, L, et al. Circulating Concentrations of Vitamins A and E in Captive Psittacine Birds. J Avian Med Surg. 2005, 19, 225–229. DOI: 10.1647/2004-004.1
3. Stanford, M. Effects of UVB Radiation on Calcium Metabolism in Psittacine Birds. Vet Rec. 2006, 159, 236–241. DOI: DOI: 10.1136/vr.159.8.236
4. Nightengale, M.; Stout, R. W.; Tully, T. N. Plasma Vitamin D (25-hydroxyvitamin D) Levels in Hispaniolan Amazon Parrots (Amazona ventralis) Housed Indoors Over Time. Avian Dis. 2022, 66, 148–154. DOI: 10.1637/aviandiseases-D-21-00117