This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Gynae), Subject name: Gynaecology & Obstetrics
Recommended daily supplement of vitamin D3 for females is: 
Select and explain. 
A. 200-500 IU, B. 500-1000 IU, C. 1000-2000 IU, D. 2000-2500 IU
C: 1000-2000 IU
Answer: C: 1000-2000 IU 
Explanation: Ans. is c, i.e. 1000-2000IURef: Leon Speroff 8th/ed, p731,734Recommended vitamin D supplementation of both males and females is 1000-2000IU/dayNote: Levels of 25-hydroxy vitamin D should be measured annually in older individualsValues less than 30ng/ml are below normalValues less than 20ng/ml is an indication of definite vitamin D deficiency