Examinations in the USA have found that some vitamin D supplements may only contain 1/10 tenth of what they claim [so instead of 5000 units you may get only 500 units and there is a whole range of these kinds of “false claims”.

Buy only vitamin D which is tested [and so in general, for all products which are not tested by a health ministry.]

Honestly, I have no if ANY Israeli supplements are tested [even for companies such as Supherb]