Answer: insufficient intake of vitamin B-12
Step-by-step explanation:
The vegan diet is devoid of Vitamin B-12 which can lead to serious health complications like anemia. The Vitamin B-12 is found in animal derived food products for example, dairy, meat and eggs. There are no plant derived food which can provide sufficient amount of B-12.
Vegetarians must ensure to obtain the adequate amount of Vitamin B-12 each day to avoid a deficiency of this vitamin.