Vitamin A is one of the most necessary nutrients for birds. It affects the reproductive, respiratory and digestive systems as well as bone and feather production, supports skin and vision health and it plays an important role in cell division and differentiation. But, what concerns us the most, as bird guardians, is the role it plays in the ability, at cellular level to fight infection. This is done in two ways, one is that it helps lymphocytes (the white blood cells that fight infection) to perform more efficiently, and the other is that it maintains the integrity of the mucosa lining of the respiratory, intestinal and reproductive tracts. Without this healthy lining and the protective mucus it produces, bacteria, virus and fungus can enter the body and produce an infection. It’s these secondary infections that are fatal to a bird with hypovitaminosis A.
Symptoms of Hypovitaminosis A (vitamin A deficiency)
Night blindness (in most cases, those ‘night frights’ are nothing more than a red flag telling us that the bird is lacking vitamin A)
High hatching mortality
Inflamed, weepy or crusted eyes
Slimy mouth or white plaque on the roof of the mouth and/or base of the tongue (the more advanced form is actual abscesses)
Labored breathing/wheezing/sneezing/tail bobbing
Nasal discharge or clogged nostrils
Poor feather color, lack of barbules, dry skin
Weight loss/lack or decrease in appetite
The tricky part about vitamin A is that, as all other fat-soluble vitamins, it cannot be eliminated from the body in its final form and it ends up stored in the liver. The body has the ability to utilize the stored vitamin when it’s lacking in its diet but, if continuously supplemented or given in very high dosages in a short period of time and because it has a cumulative effect, the liver will, eventually, become toxic and stop performing its functions. When this happens, the bird dies. Therefore, extreme care is to be taken with any vitamin/mineral supplement and any food that contains vitamin A in its final form (pellets, treats, etc).
But, thankfully, it’s not a matter of ‘Dammed if I do and dammed if I don’t’. The solution is to look to nature for the answer and that is to provide the bird with food rich in beta-carotene, the natural precursor, which the body processes into whatever amount of vitamin A it needs and eliminates the rest.
Foods rich in Beta-Carotene
Red Palm Oil Carrots and carrot juice
Broccoli leaves Red Chili Peppers
Sweet Potatoes Mango
Pumpkin Collard Greens
Dandelion greens Squash
But even when we are extremely careful about supplements, there are other reasons why vitamin A toxicity (Hypervitaminosis A) can occur and those include medications like tetracycline and poor liver function so we need to be vigilant about symptoms of this problem.
Symptoms of Hypervitaminosis A (vitamin A toxicity)
Bone pain or swelling
Brittle beak and claws
Skin discoloration and/or dryness and/or peeling and/or rashes
Sensitivity to light
Diarrhea (could alternate with constipation)
Enlarged liver/elevated liver enzymes/cirrhosis/fibrosis