- Deficiency of iron leads to decreased production of hemoglobin. This results in a condition called iron-deficiency anaemia, characterized by a reduced number of red blood cells or a reduced amount of hemoglobin in the blood, impairing oxygen transport. Symptoms include fatigue, weakness, and paleness. - Scurvy is caused by Vitamin C deficiency. - Rickets is caused by Vitamin D deficiency (leading to impaired calcium and phosphorus absorption). - Cholera is an infectious disease caused by bacteria, not a nutrient deficiency.