Good-bye, supplements! Hello, dietary calcium! But when do I eat it?

November 8, 2014 11:59 AM

Last week my family doctor told me I should limit my calcium from supplements to no more than 500 mg per day as excess calcium from supplements can cause health issues. The Canadian Osteoporosis recommendations suggest I avoid supplements entirely if possible. I can do that easily most days. But I have a question about timing: how much time do I need to leave between Glass of Milk #1 and Glass of Milk #2?

There's nothing in past Ask Mefi posts or in the recommendations about this. I'd like to know if I need to wait 1 hour, 2 hours, 3 hours, or more between servings, even if the time is approximate. Especially on weekends, I may sleep in late and then go out. So if I drink a glass of milk at 2 pm, is drinking another glass of milk at 4:30 too soon?

Information and any resources very much appreciated. Thank you!

posted by Schadenfreudian to Health & Fitness (5 answers total)

I've never heard anything at all about waiting a certain amount of time in between glasses of milk. I suspect that your doctor's concern and those of the Canadian Osteoporosis people deal only with the supplements, and assume that you are getting calcium in your foods. My non-medical advice is to drink the milk whenever it is easiest for you to drink the milk. There is also a bunch of calcium in other foods. If you want to track the calcium you're getting, either to make sure you're getting enough without the supplements, or if there's some other reason your doctor told you to limit your calcium, here's a website that tells you the calcium content in various foods. Also, just in case you can't get the UCSF website in Canada, here's the Osteoporosis Canada site, with similar information.
posted by Weeping_angel at 2:20 PM on November 8, 2014 [4 favorites]

I also have not heard anything about needing to wait between ingesting servings of dietary calcium, and when I searched for it through the AAFP and Canadian Family Practice guidelines sites, there was no mention of it (and no mention of it that I saw on the wider web either), which I would expect it should be if it were a problem, given the number of people who would be affected by it if this were an important part of the recommendation.

I did find this page that discusses how to maximize absorption of dietary calcium. These types of issues may be more important than timing of when you ingest calcium.
posted by treehorn+bunny at 5:00 PM on November 8, 2014

how much time do I need to leave between Glass of Milk #1 and Glass of Milk #2?

I'd do greek yogurt rather than milk, so ... let the glass of milk stand for a week first?

Apparently milk has a higher glycemic index than yogurt or something. (I'm not a nutrionist, obviously.)
posted by sebastienbailard at 10:37 PM on November 8, 2014

The guidance I can find suggests consuming no more than about 500 milligrams of calcium at a time. Examples:
National Institutes of Health: Calcium Fact Sheet for Consumers - "Calcium absorption is best when a person consumes no more than 500 mg at one time."
NPR: Too Much Calcium Could Cause Kidney, Heart Problems, Researchers Say - "That's because the body can only handle 600 milligrams of calcium at once."

So what constitutes "at once"? The greatest amount of calcium from food is absorbed in the ileum, the final section of the small intestine. (pdf) How long that takes will depend on several factors, but we're talking hours rather than minutes. For best efficiency, your intake would be spaced several hours apart, like at separate meals. If on some days that isn't convenient, I wouldn't give it a second thought.
posted by Snerd at 1:19 PM on November 9, 2014

Response by poster: Thanks everyone! I am reassured.

*Runs off to grocery store to buy lots of milk*
posted by Schadenfreudian at 11:32 AM on November 12, 2014