This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Nutritional Deficiencies, Subject name: Social & Preventive Medicine
Best test to detect iron deficiency in community is: 
Select and explain. 
A. Serum transferrin, B. Serum ferritin, C. Serum iron, D. Hemoglobin
B: Serum ferritin
Answer: B: Serum ferritin 
Explanation: Evaluation of iron status in the body can be done by: Serum ferritin: 'Most sensitive tool for evaluation of iron status' , especially in populations with low prevalence of anemia. Hemoglobin concentration: A relatively insensitive index of nutrient depletion. Serum iron concentration: Normal range is 0.80 - 1.80 mg/L. Serum transferrin saturation: Normal value is 30%.