<prompt> Richest source of Vitamin D -MilkEggHalibut liver oilButter  <response>: Halibut liver oil contain 500-10,000 Microban per 100g . egg contain - 1 . 25microgram, Milk 0.1micrigram per 100g.REF. PARKS TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 21ST EDITION. PAGE NO - 617 