Adora calcium supplements are awesome. For 30 calories apiece, each little disc has 500 milligrams of calcium, 40 mcg of vitamin K and 100 IU of that all-important vitamin D. And you can get 'em in either milk chocolate or antioxidant rich dark chocolate (my fave). Just remember that the body can only absorb 500 milligrams of calcium at a time, so if you take two a day, make sure they're spaced out in the morning and at night.
You can order them at Adora's site, which offers volume discounts, or find them at your local Vitamin Shoppe or Whole Foods Market. Each bag of 30 retails for around $7.