Re calcium supplements, I think the consensus is that very little is absorbed, and
it is more important to take vitamin d, which increases absorption. And
absorption is best from foods rich in calcium. Eat your spinach. Got milk? (yuck, not me).
Finally, treatments like Fosamax have been shown to work when taken regularly for at least a year. However, according to my doc, it is contraindicated for those with a hx of esophageal varisces and/or upper GI bleeding.