Final answer:
Having less than 0-500 ug/day of vitamin A can weaken the immune system, cause anemia, and lead to visual impairments, including night blindness.
Step-by-step explanation:
Having less than 0-500 ug/day of vitamin A can have negative effects on cells and lead to various health consequences. Vitamin A deficiency can weaken the immune system, making it more difficult for the body to fight off infections. It can also cause anemia and visual impairments, including night blindness and even total blindness.