If you are taking calcium supplements and iron supplements (or a multivitamin with iron), remember to allow a 2 hours time span between these two supplements. Calcium blocks the absorption of some of the iron so you would get the best benefit if you allow 2 hours between these. Take iron with Vit C
Also, for anyone who takes Synthroid (levothyroxine) or other thyroid replacement med, it is recommended that Calcium not be taken within 4 hours of thyroid hormone. Calcium chelates the thyroid hormone so there is not an optimal absorption of the synthroid.