Just interested in your responses. I give a long facepalm and explain that calcium is abundant in green leafy vegetables, as well as some fruits/nuts, and I'd rather get my calcium without lactose, casein, and hormones in the mixture
Their latest response to that is "THERES NOT ENOUGH CALCIUM IN VEGETABLES U N33D DAAARY" "NOT ENUF." "YUR BONEZZZZ", so I just tell them we've only been consuming dairy for the past 10,000 years, and ask how we survived before that.
That doesn't work so well on the young earth creationists though.