Did the Dairy Council set the RDA for calcium?
Q. The RDA for calcium seems impossible to achieve unless someone eats dairy (or takes supplements), but considering that dairy has been part of the human diet for only a short period of time (and most people are lactose intolerant), how can our requirements really be that high? Is there scientific evidence that we need that much calcium or has the Dairy Council had a hand in the government's guidelines?
A. You mean, was there a conspiracy to get Americans to consume more dairy products by setting the recommendations for calcium intake higher than necessary? I wouldn't go that far (although I'm sure some would!).
The RDA for calcium reflects the realities of the typical Western diet
The RDA for calcium represents the amount that will meet the needs of most (97%) healthy individuals. They're taking into account not only the amount needed to prevent acute calcium deficiency but also to prevent long-term consequences like osteoporosis.
This is based on scientific research, of course. But most of that research is done on people who eat a typical Western diet--which is relatively high in both protein and sodium. Coffee and soft drinks (containing caffeine and phosphates) are frequently consumed. All of these things can increase the body's calcium requirements.
The RDA for calcium reflects how much calcium it takes for someone with a typical Western diet to maintain adequate calcium stores. Those on a lower protein or lower sodium diet might require less.
Non-dairy sources of calcium
Not only are dairy products some of the richest sources of dietary calcium, but the calcium in dairy is well absorbed by the body. But if you're not into dairy, canned salmon and sardines are great non-dairy sources. Tiny bones in the fish--so soft that they're simply consumed with the flesh--are what makes these fish good calcium sources. Kale and collard greens are also good sources. A cup of collards has as much calcium as a cup of milk.
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Posted by: A-M | Oct 22, 2009 7:02:38 AM
I've often wondered about this. I am 5"2 and 1/2" and of average weight (BMI ca. 25). I am female and there is a history of oesteporosis in my family, which is why I try to make an effort to get enough calcium. But I rarely seem to hit the target.
However I do not drink alcohol or caffeine (not through any healthful choice, I just don't like beer/wine/coffee/tea) and I don't add salt to my meals. Can I get away with less and still get enough calcium in my diet?
Monica's Response: All of the recommended intakes are a "best guess" of what's going to be right for the majority of folks. Individual needs can be higher or lower and you've listed several plausible reasons that you calcium requirements might indeed by lower than the DRI. Then again, you have a family history of osteoporosis. If your primary concern is bone health, you could have a bone density scan to see if your bones are thinning prematurely. Also, keep in mind that calcium is just one issue. Not smoking, exercise, and vitamin D are also important factors in maintaining strong bones.
Posted by: R.J. | Oct 20, 2009 5:05:47 PM
Greg..that is not an unusual amount of Vit D given the fact that you have had WLS (weight loss surgery). You should make sure that you are taking some kind of calcium supplement (calcium citrate is best)due to the malabsorption factor part of the surgery. Also your doctor should be check your the vitamin D levels in your blood periodically.
Posted by: Greg | Oct 20, 2009 1:14:10 AM
I have had weight loss surgery and my vitamin D levels are quite low. My doctor has prescribed 50,000 iu's of vitamin D once a week. Is this amount taken at once safe?
Posted by: R.J. | Oct 20, 2009 12:50:48 AM
Something that seems to be missing in this discussion is the role that carbonated drinks play in osteoporosis. (Americans seem to take in a considerable amount of pop and coffee.) Then compare that with other parts of the world,especially parts of Asia. Phosporous (found in pop) will rob the bones of much needed calcium. High fat diets (generally poor nutrition) and the lack of exercise can also lead to weakened bones. Just a thought...
Posted by: Ghansham | Oct 19, 2009 10:55:28 PM
Why are thyriod patients given extra calcium .Is their RDA more. Hypo thyroids have a tendency to diebetes.
Does this lead to prostate cancer
Posted by: Rebecca | Oct 19, 2009 10:33:06 PM
I have my own dairy goats and milk 2 everyday. So I drink my milk raw and make my own cheese. I figure I get plenty of calcium that way. Goats milk is good for those that are lactose intolerant. I can't drink cows milk because I am lactose intolerant, but the goats milk doesn't bother me at all.
Posted by: Kelly | Oct 19, 2009 7:37:04 PM
The USA consumes more dairy products than any other country in the world, yet we have the highest rate of osteoporosis. Why is that? I have read that dairy is NOT a good calcium source because it's only 33% absorbable, and the protein content makes the body too acidic, and thus pulls calcium from the bones to alkalize the blood. Can you comment on that please?
Posted by: James Siebert | Oct 19, 2009 3:53:49 PM
You overlooked probably the most important issue wrt population studies to determine required Ca intake: that the _majority_ in populations studied were likely vitamin D deficient.
Posted by: Gary | Oct 19, 2009 3:31:26 PM
Monica, what is the RDQ (in mg) for calcium anway? No one ever mentions it. :)
Posted by: David Whyte | Oct 7, 2009 9:16:04 PM
I had a dynamic and fascinating lecturer in biochemistry who used to give practical and interesting examples of biochemistry.
One he gave was that pasteurization of milk changes the properties of the casein molecules. In raw milk calcium (and magnesium) are bound to the outside of the casein so off spring find it very easy to absorb the calcium.
However when you pasteurize you change the shape of the casein. The casein comes "inverted" so that the calcium is now on the inside of the protein. Thus it is no very bio available, as it is locked away on the inside instead of the outside.
The result is that pasteurized milk produces are not the great calcium source they are made out to be.
Posted by: Jamie | Oct 6, 2009 6:04:36 PM
B,
The world-over, a very large percentage of people are in fact lactose intolerant. I'm not sure of the percentage but more than 50% would not surprise me. People with ancestors out of Northern Europe are the least likely to be intolerant.
Posted by: B | Oct 6, 2009 1:45:00 PM
I live at roughly 32 Degrees North and according to that website Monica posted, in the summer it only takes 2 minutes of sun exposure to get 100% RDA for Vitamin D and even in the winter it only takes 10 to get 100% RDA. I bring this up because a couple other posters forgot to consider location into amount of Vitamin D production. :)
P.S. Most people lactose intolerant? LOL source?
Posted by: Darya | Oct 6, 2009 10:37:05 AM
I rarely eat dairy and don't take supplements and my calcium levels are plenty high. I eat a very balanced, healthy diet of whole foods.
Most of the studies that give calcium supplements and look at osteoporosis endpoints show it to be completely ineffective.
Also, excess calcium causes prostate cancer in men Dairy products using cows milk are implicated in several autoimmune diseases, including multiple sclerosis and type 1 diabetes.
Posted by: Pete | Oct 6, 2009 7:43:26 AM
Given sufficient vitamin d almost everyone can extract the calcium they need from their diet. Adding calcium to your diet without increasing vitamin d intake has no effect.
If you are a vegetarian or vegan and need more calcium just eat chalk or grow your vegetables on calcium rich soil (buy ground limestone from your garden centre). This is exactly what out tortoise does (he is a vegetarian). He also spends the midday basking in the sun so he has plenty of vitamin d (he also has a UVB sun lamp for the spring and autumn. when the sun is too low in the sky). Pity we don't provide the same help for our elderly.
Posted by: Pete | Oct 6, 2009 7:34:09 AM
Katherine is unfortunately incorrect, most people cannot get enough vitamin d from 15 minutes exposure. If you are white (not tanned in any way), it is summer, it is midday and there is no cloud or smog and you can take most of your clothes off and lie down you will make enough is 15mins. Otherwise no. You cannot make vitamin d from sun light 1) in winter 2) when the sun is low in the sky 3) if you wear make up on the exposed skin 4) If there is any smog 5) you have darker skin.
Posted by: Heather Schultz | Oct 5, 2009 5:43:37 PM
I wonder if the Kale that's been roasted, to make the chips, is just as nutritious as the raw kind, or the kind put into soups/stews?
Posted by: TTC | Oct 5, 2009 5:28:12 PM
I wouldn't call it a conspiracy, but yes, the dairy industry does decide (for the most part) what information the public hears/doesn't hear about dairy products and calcium.
I'm still waiting for the dairy industry to explain why osteoperosis is rarer in Japan than in Western countries, even though:
-the average Japanese consumes 1/3rd the amount of dairy as the average Canadian
-the average Japanese intakes a modest ~500mg of calcium per day
And I don't want to hear any of the "they have different genes" nonsense. 3rd and 4th generation East Asians in America/Canada have similar rates of disease as everyone else, so it's clear that environment outweighs genes considerably.
Posted by: Katherine | Oct 5, 2009 4:51:01 PM
Another truth about calcium, those who do not consume animal products absorb greater amounts of calcium from vegetables than do meat eaters. Meaning that if a meat eater and a vegetarian eat both eat 1 cup of collard greens, the vegetarian's body will extract more calcium from the greens than the meat eater's body will.
Dave, vitamin D deficiency has recently been linked to an "inflammatory" diet. The root cause of the epidemic is that most people in the U.S. have no idea how to eat properly. A healthy person on a healthy balanced diet can get adequate vitamin D from 15 minutes of sun exposure.
Posted by: Dave Moss | Oct 5, 2009 1:51:45 PM
And don't forget the (nigh universal) vitamin D deficiency! (Quite high levels of vitamin D being needed to optimise calcium utilisation).
Oh and also the widespread magnesium deficiency... which might mean that we absorb more calcium, but which means that we are far less able to do anything useful (such as build bone) with it.
