Is it okay to swallow calcium supplements with orange juice or does the orange juice make the calcium less absorbable.

OK: Orange juice doesn't reduce absorption of calcium supplements and improves absorption of calcium carbonate. It is also important to have adequate Vit D; most adults need at least 5000 iu/day in fall and winter. See http://www.webmd.com/osteoporosis/calcium-supplements-tips But best to get calcium from diet; please also see https://chriskresser.com/calcium-supplements-why-you-should-think-twice/