Skip to main content
ask a health expert

Creatas Images

The question

How much caffeine is it okay to consume in a day?

The answer

Health Canada contends that a maximum intake of 400 milligrams of caffeine per day is safe for healthy adults – an amount found in about three small (8 ounce) cups of coffee.

Women of childbearing age should limit caffeine intake to 300 milligrams per day as some evidence suggest that heavy caffeine intakes increase the risk of miscarriage.

During pregnancy, I advise women to consume no more than 200 milligrams of caffeine per day.

Children should not consume more than 45 milligrams (4 to 6 years), 62.5 milligrams (7 to 9 years) and 85 milligrams (10 to 12 years) of caffeine per day.

Caffeine may have some health benefits. The caffeine in coffee helps treat asthma symptoms, enhances physical performance and boosts mental alertness. Coffee's protective effects against gallstones and Parkinson's disease are also attributed to caffeine.

But caffeine is not for everyone. Studies suggest that excess caffeine can boost blood pressure and heart rate, a concern for people with high blood pressure and heart disease.

In postmenopausal women who don't get enough calcium, consuming more than 400 milligrams of caffeine per day has been linked with having a lower bone density. (Caffeine increases the amount of calcium your kidneys excrete in the urine.)

And because individual caffeine tolerance varies widely, even a small amount can cause sleep disruptions, headaches and anxiety in some people.

If you need to cut back on caffeine, start by avoiding caffeine in the afternoon. Choose caffeine-free or decaffeinated beverages like herbal tea, mineral water, fruit and vegetable juice or decaffeinated coffee.

Reduce your caffeine intake gradually over a period of two to three weeks to help prevent withdrawal symptoms such as headache and muscle soreness.

Send dietitian Leslie Beck your questions at She will answer select questions, which could appear in The Globe and Mail and/or on The Globe and Mail web site. Your name will not be published if your question is chosen.

Read more Q&As from Leslie Beck.

Click here to see Q&As from all of our health experts.

The content provided in The Globe and Mail's Ask a Health Expert centre is for information purposes only and is neither intended to be relied upon nor to be a substitute for professional medical advice, diagnosis or treatment.