How to prevent calcium loss when drinking a lot of coffee? I'm recently drinking a lot of coffee at work. I'm worried about the health issues - lost of calcium from the bones.

How can I prevent calcium loss? Drinking coffee with milk is out of option for me - I'm lactose intolerant.
Apparently, drinking caffeinated beverages shouldn't affect you calcium level if you get your recommended daily intake of calcium. According to this review of the literature on the subject:


  There is no evidence that caffeine has any harmful effect on bone
  status or on the calcium economy in individuals who ingest the
  currently recommended daily allowances of calcium.


That said, there does seem to be a connection between high caffeiene intake and low calcium intake, meaning that there is significant overlap between individuals who drink caffeinated beverages and don't get enough calcium from their diets, but implying a causal relationship is dubious. Luckily,


  ...the negative effect of caffeine on calcium absorption is small enough
  to be fully offset by as little as 1-2 tablespoons of milk.


Most milk alternatives (like soy or almond milks) are fortified with calcium and other nutrients and drinking them in place of milk should do the trick, just be mindful of the high sugar content of many of the milk alternatives available.

Also, I wouldn't worry about your daily coffee dose, 1.4 billion cups of coffee [2] are poured every day and if there were serious health risks associated with daily caffeine ingestion, we'd know about them!