Living in the northern latitudes means D3 deficiency is likely an epidemic, although one few people are fully aware of (and this includes medical professionals/NHS). I take between 4800iu and 7200iu daily as is recommended by the most advanced research on supplements. One needs to be careful though, because "Vitamin D" is really a hormone and taking too much can be as/more harmful as/than being deficient.
It is hard to get Vitamin D3 in single doses over 1000iu, so for this reason alone I am very pleased with this product. Further, this is D3 which is the form that the human body requires (Cholecalciferol) and it contains no wheat, gluten, etc. Finally, it comes in a softgel serving which studies have shown to be the best way of assuring full absorption.