How much Calcium and Vitamin D should I be taking?
This has been a question that has been studied and re-studied over the past several decades, and it seems we are still being given conflicting reports.
In my previous post, Do the “D”!! (Vitamin D) , I stated that to have healthy bones, and also possibly help to avoid other diseases like breast and prostate cancer, Multiple Sclerosis, and Diabetes, most people would benefit from taking Vitamin D in a supplement form in doses up to 2000 IU. This was based on several recent studies that have changed the way we think about Vitamin D and its role in disease and cancer prevention….especially the study that found low Vitamin D levels in women diagnosed with breast cancer.
A recent report, however, was published by the Institute of Medicine and is making the rounds of the health blogs, health news shows, and magazines…Time Magazine for one. This report looked at hundreds of studies done in the US and Canada on the health benefits of Calcium and Vitamin D and the necessary amounts that are “recommended”.
They concluded that the RDA (Recommended Daily Allowance) has been over-stated for years and the actual RDA for “healthy adults” for Calcium is 1000mg/day and for Vitamin D, 600 IU/day. This is not the amount that you should be taking in a supplement, rather it is the amount you should be taking in each day. This could be from food or the sunlight. Anything short of these amounts should be supplemented to meet the RDA.
While the IOM is a very credible institution, I have several problems with their conclusion.
- The recommendations are strictly for bone health. They did not address the need for vitamin D for any other system other than the skeletal system.
- No where can I find and example of the “thousands of studies that are included in this report”. The studies are from 1997 and on, but the most recent studies (on Vitamin D in particular) are the ones that are showing the most credibility and are the one’s that are changing the way breast cancer, for one, is being screened and possible prevented. It’s unclear that these recent studies were included in the report.
- The RDA for Vitamin D is the same for ages 1 – 70 years (600 IU/day). Really? A one-year-old baby boy has the same recommendations as a 40 year old woman? Does this sound wacko to anyone else?
- The OIM used data on random blood samples of people in the US and Canada and tested their Vitamin D level. A majority of “healthy adults” had blood levels of at least 20 mg/dl, which IOM stated is a sufficient level and therefore concluded that most people don’t need any additional supplementation. However, normal blood levels of Vitamin D range from 35 – 74 mg/dl in most labs across the country, and for breast cancer prevention, the magic number is “as close to 100 as you can get without going over”. Any woman with a Vitamin D level of 20 mg/dl would be told (by any doctor not living under a rock) to start 1000 IU of Vitamin D daily and return for a repeat level in 6 weeks.
With each report that looks at Vitamin D, the RDA for Vitamin D increases. Once thought to be 100 IU/day, the previous before this report was 200 IU/day, and now with this most recent report it is 600 IU/day. (do you see a trend here?)
The OIM did say that the “upper limit of intake” was 4000 IU and could find no harmful effects of taking that amount daily. The risk of adverse effects increased with increasing doses from there.
This is one report.
I still stand by the 1000 – 2000 IU supplementation recommendation based on recent (within the past 5 years) studies and based on the change in findings for prevention and Vitamin D. Better yet, if you can get your blood level checked and supplement from there, that is ideal. While studies are still being conducted and nothing is 100% conclusive (other than that you will die someday), it makes a hill of sense to be safe but cover your bases. Vitamin D is inexpensive and easy to take. To the new recommendations I say…no thanks.