Just use the plain calc no d3 for a month and then go lightly with the d3 twice a month after that. You should also have a vitamin supplement. Preformed vit A such as reptivite twice a month. Another method is getting vit A gel caps, poke with a pin and put a little drop on a feeder once a month. I like to dust with bee pollen regularly along with the plain calcium. Arcadia earth pro is a nice supplement to alternate with the plain calc as well if you'd like.