Hi, I’ve just had a nasty shock with an ankle injury. The result is I am taking Evacal D3 and analysing my diet, which I think wasn’t too bad from a calcium point of view, although I’m improving it. However, I had not previously realised that some foods inhibit calcium absorption. From what I would normally eat bran flakes and rhubarb (when the garden produces) seem to be the main culprits. So they’re off the menu now. However, I read that porridge oats can have an affect on calcium absorption, although not so much if you soak them first. Does anyone know of any data on this? I realise this is rather petty in the big scheme of things but I really don’t like having cornflakes for breakfast every day (as an evening snack fine), but if porridge is not good I’ll have to change. Context: diagnosed with osteopenia about ten years ago and waiting for another DEXA scan. Like I imagine everyone else on this forum I want to do the best for my bones.
Hi Jill999, and welcome to the online community!
https://pubmed.ncbi.nlm.nih.gov/8558315/
I managed to find an abstract on the NIH website that seems to suggest that the absorption of calcium is inhibited by wheat bran.
My search on rhubarb was inconclusive, with an NIH abstract suggesting that it doesn’t inhibit calcium absorption, but other websites suggesting it does…
My take from the research that I have done though seems to suggest that for both it only prevents absorption of calcium from the food present in your stomach when they are eaten, not on an ongoing basis. So, if you fancy an occasional bit of rhubarb and custard, then it’s not going to do much harm in the long term, and you can make up the lost calcium at another meal.
It all comes down to having a balanced, varied diet that will provide you and your bones with the nutrients that they need 
Thanks Flutterby, thats really helpful. I am very patrial to rhubarb with greek yogurt :-)
Hello, I recently discovered this too re food and absorption when looking into why my calcium levels weren’t improving despite taking more calcium. I also learnt that the body can’t absorb more than about 500mg of calcium at anyone time (it actually has the opposite effect - the more you take the less that is absorbed), so if taking more than that as a supplement it is best to spread it through the day. I too have a wheatbran based breakfast and heard wholegrains (like oats which I also have everyday) and beans also inhibit absorption. I have access to research papers in full due to my work and from reading the whole papers, it is okay within about a 2 hour window from what I remember.
The first thing I would suggest, is consider all of this in relation to your blood results re calcium.
For example, in my own context, I spread 1500mg calcium (citrate as the amount of carbonate I had to take previously caused issues with my digestion) in three 500mg capsules through the day and took them a few hours before or after eating the inhibiting foods. My levels still remained low. I then tried 625mg x 3 and they are now normal for the first time. One could say I have to take a higher dose of calcium due to the inhibiting foods, but from my past history with calcium levels, it could equally be that because I don’t eat diary, I need a higher dose. I also think this needs be looked at with health in a holistic manner - these foods I eat for nutrition and fibre. So I balance with overall health rather than remove these foods and my calcium levels are now normal.
I hope this helps!
Thanks, That’s extremely interesting. I am back on the bran flakes for its digestive properties. I have on average a pint of milk a day and I was disappointed to find that some of that was sort of “wasted” calcium intake as my cereal was preventing its absorption. I am no doubt over thinking it but just out of curiosity have you seen anything on how long it takes for the body to absorb 500mg of calcium?
Did it show in your blood results that it was being inhibited? If your adjusted calcium levels are fine, then it suggests in your overall diet your calcium intake is fine.
Hi Jill999,
Lawrence here. Interesting comments above, especially for me the fact that it’s hard to absorb more that 500mg calcium per day. I take 700mg and eat dairy. Re drinking milk, I would say not all milk bring the same benefits. I buy raw full cream milk and Kefir from a farm in Cheshire (they deliver everywhere in UK). I eat oats for magnesium but best to soak them overnight. In fact most suggest a calcium/magnesium ratio of 2:1. I follow advice of 1:1 as magnesium is needed for calcium absorption and most people seem to be deficient in magnesium for various reasons. However, good to remember that each one of us has a different metabolism and history, which means that I don’t believe in one solution fits all. Having said that there is knowledge out there that is worth exploring. E.g. I have started being more careful regarding foods like rhubarb and spinach (both mentioned in a paragraph on the ROS website), issue mentioned by Jill999. The issue is due to Oxalic Acid (OA). OA binds with minerals (calcium, magnesium etc) to form oxalate crystals instead of minerals going to our bones. Our body apparently gets rid naturally of some OA mainly through stools but there is controversy about how much is excreted and how much remains trapped in the body as oxalate crystals that are harmful depending on the amount and where they settle (any body part can be affected, like articulations). One OA expert is Sally K Norton (check her website), her latest book “Toxic Superfoods” gives a basic list of the main foods to avoid with high amount of OA. You’ll be surprised ! She has majorly improved her health through stopping or reducing OA. Not surprising we can be ill if we are depriving our bodies of main minerals and load the body with harmful oxalate crystals. Medical research vs empirical research, interesting subject. A few months ago I decided to take this OA issue seriously. My next DEXA scan is Jan 2027. If my results show improvement I’m happy to share more with this community, keep fingers crossed for me please, thank you. I’m not at present taking any osteoporosis treatment. Lawrence
Hi, apparently my calcium levels in my blood is ok. I just want to make sure I’m getting plenty of good bone food. I was a bit miffed to find I’d been having branflakes and it would be inhibiting calcium absorption. I think what I’m taking a bit from all this is its better to not eat all your calcium at once. It’s not to hard to leave two hours after bran flakes for breakfast before my Evacal tablet and any more food. Basically if there’s calcium in there I want to give it the best chance to do its stuff.
Thanks, I’ll check out the foods with issues. Back on the bran flakes but I don’t need to eat rhubarb - and my chum is happy as she’s getting what comes off the very small amount my garden produces. I don’t think I’ve ever actually had spinach and I don’t need to start now. Interestingly (perhaps) a few years ago a friend of mine ate a lot of spinach as he thought it would be a good idea, the end result was he gave himself some problem - I forget what - but it was easily solved by not eating spinach with every meal. I hope nothing bad ever hits the headlines about carrots as they are my favourite vegetable and I have them every day. I must admit I took the absorption thing as meaning if for example I drank a pint of milk and then immediately had a large helping of greek yogurt with chunks of cheese stirred in (yick?)) my body would not take all the available calcium on board so better to spread it out throughout the day if you can… Actually a bit of me is now wondering what greek yogurt with bits of cubed cheddar stirred in would taste like…
@Lawrence the body can absorb more than 500mg per day, I meant at one time. i.e if you ingest 1000mg calcium tablet you would absorb less calcium from that than you would if you took it in two 500mg tablets at different times in the same day.
Hi everyone,
We just wanted to drop in and share a few links to our information about nutrition for bone health , for anyone who comes across this thoughtful conversation and would like to read a little more. 
Thank you to the members who have already kindly mentioned some of our resources:
Are there any foods I should avoid?
Calcium
Calcium-rich food chooser
Eating well for your bones
Wishing you all the very best,
Lulu
ROS Moderator