Nutrition of parrots and other pet birds (Merck): seed-diet calcium/vitamin A imbalance
Source: Merck Veterinary Manual article "Nutritional Diseases of Pet Birds" (first-hand, retrieved 2026-07-29 via curl, HTML stripped to plain text). All bullets are exact verbatim substrings of the cited source_file and C1-substring verified.
Seed-diet deficiencies in psittacines (parrots)
Seed-based diets are well known for their calcium:phosphorus imbalance and amino acid deficiencies.Sunflower seeds, which tend to be selected preferentially by many psittacines, are low in calcium, deficient in essential amino acids, and high in fat.seed diets and even mixed diets of ½ seeds and ½ pellets (if not portion controlled) are deficient in vitamin A.