Always keep a look out for orange cystals in the poo (i.e. calcium oxylates) this can be an indicator of a need to back off from supplements.
Picked this tidbit of advice up elsewhere and think it's worth passing onto the good folks here.
Essentially a good rule of thumb to follow is VERY LIGHTLY DUST THOSE BUGS , with suppliments, less is more (a wee bit of high school chemistry - for those who took it , remember those solubility products ? --- supps have limited water solubililty), adding too much (CAKING THOSE BUGS with dust) wont help.