I think the ACV twice weekly is enough without the citric acid also. To be able to utilize calcium properly, just receiving it for 3 days of egg laying isn't enough. Should be getting it regularly during the month, but not every day, to be able to utilize it properly.Yes I give apple cider vinegar twice a week, citric acid twice a week and a mix of proviboost+ vancalp-c + liv 52 thrice a week in the Drinking water.
I also give calcium d3 to females during the three days of egg laying once in the evening. So this should not be the reason.