When Shakespeare wrote “timing is everything,” I don’t think he was concerned about whether to take a calcium supplement after drinking coffee, whether he had to eat fruit alone or when to brush his teeth.

A reader posed these questions and I learned some new facts after my research.

A Google search reveals many articles stating that caffeine inhibits calcium absorption. But medical experts take a different view. Consider the view of Dr. Robert Heaney, a professor at Creighton University’s medical school. Writing in the journal, Food and Chemical Toxicology 2002, he stated: “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.”

Knowing the form of your calcium supplement is most important. Calcium carbonate needs to be taken with food; calcium citrate can be taken on an empty stomach. Calcium is best absorbed in 500 mg doses. Iron can interfere with calcium absorption so avoid taking calcium with a multivitamin with iron or an iron-rich meal. Iron-rich foods include beef or chicken liver, chicken and fish as well as beans, spinach and tofu.

The reader’s second question concerned a belief that fruit should be eaten alone, not with a meal. The myth-busting site Snopes found this confusion circulating on the Web in 1998. Whether you eat fruit with a meal or on its own, it still will be digested and absorbed. Our digestive tract is complex and can handle what comes down the pipe.

The last question was whether you should wait 30 minutes after eating before brushing. Tooth enamel is weakened after eating acidic food. If you brush while the mouth is in an acidic state, enamel can be removed. Fruit juice, wine, vinegar, soda and sports drinks lead the list of acid-producing foods. Cheese and nuts neutralize the mouth. So whether to brush right away depends on what you eat. For a list of acid-containing foods check out http://www.pronamel.us .