Quote from Dr. Garrett Smith on January 18, 2019, 9:55 pm

Vitamin A toxicosis in a lorikeet flock.

Vitamin A toxicosis has recently been recognized as a concern for granivorous birds such as cockatiels (Nymphicus hollandicus) and nectarivorous birds such as lorikeets. Such birds have little exposure to performed vitamin A in their wild diet, relying on carotene conversion to supply their vitamin A needs. Multiple clinical problems arose in a lorikeet flock when excessive vitamin A supplementation was used.

The lorikeets don't eat retinoids ("animal Vitamin A") ever in their wild diet, and thus they don't ever need it!  Give it to them, and they get poisoned quickly!  The refusal to understand and use simple evolutionary biology principles by people who are supposed to be smart just boggles my mind.  "Multiple problems"...see below for the full list, it should scare the heck out of you while also looking extremely familiar.

Current Therapy in Avian Medicine and Surgery

Specific health problems resulting from lorikeet diets

There are several health-related issues resulting directly or indirectly from the diet fed to lorikeets. The high sugar content of the diet can lead to yeast/fungal and bacterial infections. This is evident in many postmortem findings by the author, even if only as a terminal event. Similarly, the sticky and moist nature of the droppings and the high sugar content of the nectar, dry food, and fruits fed can provide an ideal environment for bacteria and yeast to proliferate on aviary structures if suitable hygiene practices are not maintained. The high energy content of most diets combined with a lack of activity in a captive situation can lead to obesity-related disorders, including but not limited to fatty liver disease and infertility [also Poison/"Vitamin A" toxicity related]. High iron content found in many human cereals and other foods used in lorikeet diets can lead to iron accumulation in various organs, but particularly in the liver, and iron storage disease. The exact nature of this problem in susceptible species requires further investigation, in particular the presence and activity of enzymes involved in iron homeostasis such as hepcidin, ferroportin, and hephaestin. High dietary vitamin A levels may also aid iron absorption and contribute to this problem.⁵

There is some evidence that captive diets may contain excessive amounts of preformed vitamin A leading to hypervitaminosis A.^87-89A study of wild rainbow lorikeets showed them to have hepatic vitamin A concentrations between 29 and 56 mg/kg, which was much lower than captive rainbow, purple-crowned, and musk lorikeets whose hepatic vitamin A levels varied between 97 and 4093 mg/kg when fed commercial nectar mixes containing up to 9990 IU vitamin A/kg.^88,90 It was also demonstrated that wild birds transferred to formulated diets had rapid increases in hepatic vitamin A levels of 90 mg/kg after 1 month rising to 588 mg/kg after 6 months. Clinical signs of hypervitaminosis A noted in lorikeets include problems with breeding and embryonic mortality; feather, skin, and beak condition and pigmentation; liver disease; and death. Increased susceptibility to infections and vitamin E deficiency were also implicated.^88,89

Although dietary vitamin A requirements for poultry and pet birds have been set at 2500 to 5000 IU/kg of food,⁷⁰ cockatiels have been found to have lower requirements of 2000 IU/kg.⁹⁰ No exact studies have been performed on lorikeets. However, it is suspected that their requirements may be even lower than this, with levels as low as 1000 IU/kg suggested as possibly toxic.⁸⁷ Lower dietary vitamin A levels supplemented with dietary vitamin A precursors may be a more suitable form of supplementation. This may also allow for adequate absorption of other fat-soluble vitamins such as vitamin E, which otherwise would suffer from competitive inhibition by high dietary vitamin A levels. It has been suggested that nectarivorous birds rely on provitamin A carotenoids for their vitamin A requirements and would ingest very limited amounts of preformed vitamin A. McDonald and Oldfield⁸⁷ have even suggested that in the absence of data identifying whether lorikeets have a requirement for preformed vitamin A, (retinol) their diets should only be supplemented with 0.15% spirulina (1440 mg/kg β-carotene), which is sufficient to support the vitamin A requirements of cockatiels.⁹¹

Chronic health problems associated with Poison/"Vitamin A" toxicity in lorikeets (see how many of these you can identify in Westernized countries as epidemics!):

• Obesity
• Fatty liver disease and other liver diseases
• Infertility
• Iron overload
• Breeding problems (human equivalents would likely be hormonal problems, low libido, sexual dysfunction, etc.)
• Embryonic mortality (eggs not making it to hatching, the human equivalent would be miscarriage)
• Skin problems, including skin pigmentation issues
• Increased susceptibility to infections
• Vitamin E deficiency and all the diseases that are associated
• Death

It's like a laundry list of Westernized chronic disease.

Current Therapy in Avian Medicine and Surgery