Birds or mammals fed mainly a fish diet should receive what supplement to prevent a serious vitamin deficiency?

• A. Riboflavin (B2)
• B. Thiamine (Vitamin B1)
• C. Vitamin C
• D. Vitamin A

Answer: (B)

A fish-heavy diet can cause thiamine deficiency in birds and mammals because some prey fish contain thiaminase, an enzyme that destroys thiamine and reduces its availability. Thiamine (vitamin B1) is essential for energy metabolism and nervous system function, so when thiamine is depleted, animals can develop serious neurological problems. Providing thiamine as a supplement directly addresses this specific deficiency risk, preventing signs like weakness, tremors, or seizures. The other vitamins listed aren’t the primary concern with a fish-based diet, though they’re all important for overall health.