Effects of Coffee and Tea on Bone Health

The link between caffeine intake and bone loss is not clear, as many studies have shown. Researchers have found a higher rate of spinal bone loss among coffee drinkers (3 or more cups per day), but bone loss in the hips and legs seem uneffected by caffeine consumption.

A number of other studies have come up no other evidence, and none of the results were very significant when bone loss was detected.

Though caffeine/coffee has little effect, tea does seem to improve the strength of bones in women. Flavonoids and fluoride may be behind the benefits of tea. 1200 British women were studied, and those who considered themselves 'tea drinkers' had stronger bones than those who did not drink tea. How much tea is needed to get any bone benefits was not recorded. Adding a bit of milk to your tea adds an extra calcium boost.

References
Curbing Caffeine May Benefit Bones
Tea May Aid Bone Health
Coffee drinking: a minor risk factor for bone loss and fractures
Caffeine, Sugar and Bone Loss