There’s no doubt you’ve heard about Vitamin D here and there recently. It is the most popular and definitely receives the most attention from health advocates of all the vitamins currently.
The recommended daily allowance as of a 1997 review was for 400 IU per day of vitamin D with most people saying there was no risk of taking high levels of supplements. Many health experts were saying that 400 IU was not enough and that there was a large portion of Americans who had low levels of vitamin D.
There are also a lot of claims out there about how vitamin D levels may influence risk for disease, including cancer. Therefore, the Canadian and American Governments asked the Institute of Medicine to do a comprehensive review of all the evidence to date regarding Vitamin D and make some recommendations. Here’s what they came out with last week:
New Vitamin D and Calcium Recommendations
Remember that these recommendations are based on all the evidence to date. That doesn’t mean that in 5 years after more research, they won’t find something different. That’s why it’s so important to have these reviews regularly. They also function as a great place to identify gaps in knowledge where future research needs to be done.
Here are the new recommendations put out this past week. (You can read a summary of the report here: http://www.iom.edu/Reports/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D.aspx). Update: report is no longer available at this link
“Overall, the committee concludes that the majority of Americans and
Canadians are receiving adequate amounts of both calcium and vitamin D.
Further, there is emerging evidence that too much of these nutrients may
be harmful.”“Kidney stones have been associated with taking too much calcium from
dietary supplements. Very high levels of vitamin D (above 10,000 IUs per
day) are known to cause kidney and tissue damage.”
The new recommended intake levels for Vitamin D and Calcium are the following:
RDI (Recommended Dietary Intake) for Vitamin D
600 IU 19-70 year old adults
800 IU 71+ year old adultsUpper Limit for Vitamin D
4000 IU for 19+ year old adultsRDI for Calcium
1000mg 19-70 year old adults
1200 51+ year old women
1200 71+ year old adults
Upper Limit for Calcium
2500mg 19-50 year old adults
2000mg 51-70 year old adults
The report also found that there was not consistent agreement among experts about what the cutoff level should be to define someone’s level as low. They report that:
“Before a few years ago, tests for vitamin D were conducted infrequently.
In recent years, these tests have become more widely used, and
confusion has grown among the public about how much vitamin D is
necessary. Further, the measurements, or cut-points, of sufficiency and
deficiency used by laboratories to report results have not been set
based on rigorous scientific studies, and no central authority has
determined which cut-points to use. A single individual might be deemed
deficient or sufficient, depending on the laboratory where the blood is
tested.”
They conclude that:
“The number of people with vitamin D deficiency in North America
may be overestimated because many laboratories appear to be using
cut-points that are much higher than the committee suggests is
appropriate.”
What does this mean for you?
There are some good practical things you can take from these recommendations and there are also some very ambiguous parts that you might not be sure what to do with! So here’s my take on it.
First off, if you choose to take supplements of Vitamin D and Calcium, we know for sure that adequate levels will be beneficial for bone health. However, if you take levels that are too high, you may be putting your body at risk for adverse health effects, which is definitely not what you want!
Be sensible with your supplementation. And make sure that you pay attention to all of your sources of Vitamin D and Calcium. Now that many foods have fortification, and some bone health medications include vitamins and minerals in them, you might be getting more than you think.
And as always, understanding and interpreting your labs is something that is important for you to do with a trusted health provider who can evaluate your entire health history. For most people, this would be your physician. If you are deemed low or deficient in Vitamin D, you may need a very high supplement dose. As long as you are on those high doses, regular lab tests are necessary to know when your levels are back to normal.
What will Julie do?
I will stick to the current supplementation that I am on, which is nothing other than an 800 IU Vitamin D pill here and there, when I remember! Most of the time, for the general public or cancer survivor who has normal labs, I recommend 1000 IU of vitamin D daily, if they want to take a supplement.
And of course, make sure that you are eating a balanced diet that will give you all the complementary health promoting nutrients. It doesn’t make much sense to take supplements if you aren’t going to focus on the foods that you are eating!
In the next post, I will focus on what we know specifically about Vitamin D and cancer prevention and survivorship. Email me or post your questions on www.CancerDietitian.com and I will do my best to address them!
– Julie
