In a well nourished person, vitamin A stores are generally sufficient to last many months on a vitamins A-deficient diet before signs of deficiency appear.
|Vitamin A structure|
The initial symptoms of vitamin A deficiency are night blindness and keratinization of hair follicles. Night blindness usually becomes apparent when the patient enters a dark place or is caught in the glare of oncoming headlights while driving at night.
Continued deficiency leads to damage to eye tissue and irreversible blindness. Vitamin A deficiency interacts with other nutrients deficiencies and with infection, worsening respiratory infections or diarrhea and causing countless deaths.
Vitamin A: symptoms of deficiency