Like Spiky, I use the Bariatric Advantage calcium citrate lozenges. Yes, a chalky texture, but flavor is good, they contain 500 mg calcium citrate each, and you can just suck on them if you don't want to chew them. And they are easily portable in purse or pocket, just wrap in a little plastic wrap and you're good to go.
The chewies are also pretty good, and they haven't caused me any gastro symptoms, but I only take 1 or 2 of them a day at most.
If all else fails, buy yourself a pill cutter. I have one that I got at Walmart for about $5.00. Works great! I can't swallow those big pills and it's not DS related, so it isn't going to get better. But there is always a way to get those pills down, you just have to see what alternatives work for you.