<prompt> True about vitamin K is:It is required for synthesis of factor VIILong term use of antimicrobials can cause deficiency of vitamin KIt is a water soluble vitaminDVT is associated with vitamin K deficiency  <response>: Ans. B Long term use of antimicrobials can cause deficiency of vitamin KRef: KDT 8e p661Vitamin K is involved in activation of factor II, VII, IX and X not synthesisIt is a fat soluble vitamin like Vitamin A, D and E. Vitamin B and C are water soluble.Warfarin an inhibitor of vitamin K is used for treatment of DVT.Long term antimicrobial use can alter gut flora leading to deficiency of vitamin K. 