I have heard a lot of talk recently about the effect of caffeine on calcium absorption. Some argue that caffeine reduces calcium absorption, so any milk that is in a caffeinated beverage, such as a latte, does not have the normal positive effect on bone health. It was also speculated that a calcium supplement should not be taken with coffee. This was concerning to me since a moderate percentage of the calcium I consume on a regular basis comes from the milk in my coffee drinks; this is also the case for many Americans. I investigated the topic to get some solid research or evidence. What I found was, for the most part, reassuring.
The majority of the research that I found concludes that caffeine does not have a negative effect on calcium absorption. It is, however, acknowledged that there may be a slight effect for heavy coffee drinkers that take in upwards of four cups of coffee per day, but even this effect would be counteracted by one or two tablespoons of milk. (Check out this article for more information: http://www.ncbi.nlm.nih.gov/pubmed/12204390)
Even though it appears that my morning latte effectively provides me with about 150 milligrams of calcium, there is a bigger takeaway message: we should never rely on a single source of calcium. To optimize absorption, we should be consuming rich sources of calcium throughout the day. An example of this would be a skim latte with fruit and low-fat yogurt in the morning, followed by a tofu (made with calcium sulfate) salad for lunch, and salmon with feta and spinach for dinner. Such a diet includes a variety of nutrient-dense foods so that absorbable quantities of calcium can be taken in from a range of sources, thus optimizing absorption. So go ahead and drink that morning coffee, but be sure to follow up with different forms of calcium all day long!