Vitamin D’s Flawed Recommended Daily Allowance
by Vin Miller
While it’s great that the FDA requires supplement and food labels to contain percentages of daily recommended values, these numbers can often be misleading. Vitamin D is one of the most important substances in regard to supporting good health and also happens to have one of the most misleading Recommended Daily Allowances.
If you look at the label on the back of food or supplement packaging, you’ll see a list of nutrients that specifies the amount of each nutrient contained in a single serving of the product and what percentage of the recommended Daily Value that this amount represents. The FDA requires food and supplement manufacturers to include this information on the labels of their products to help you determine how much of your daily recommended allowance you’re consuming.
What Exactly is the Daily Value?
The Daily Value is the recommended daily intake of a particular nutrient and is generalized based on a 2,000 calorie diet. For vitamins and minerals, the Daily Value is based on a standard called the Reference Daily Intake, which is based on an older and more familiar standard called the Recommended Daily Allowance, or RDA. The RDA was originally developed by the National Academy of Sciences and is intended to represent the amount of a nutrient that should be consumed on a daily basis to avoid deficiency and any of the health conditions that would be likely to follow.
Are Daily Values Important?
The one thing that’s certain about Daily Values is that their derivation can be quite confusing! However, for someone who eats a well rounded diet based on natural whole foods such as meat, fish, fruit, and vegetables, Daily Values are less important because such a diet provides plenty of the nutrients needed to support good health. While Daily Values are much more useful for people who use a lot of supplements, they can also be very misleading.
Why Daily Values are a Flawed Standard
The primary shortcoming of Daily Values is that they’re based on RDAs. In many cases, the RDA is nothing more than the minimum amount of a nutrient needed to prevent a particular condition that’s caused by a deficiency of the same nutrient. This is misleading because the amount of a nutrient needed to prevent a disorder can be significantly lower than the amount needed to support optimal function and health.
The Misleading RDA for Vitamin D
Robert Heaney MD, a prominent vitamin D researcher, served as a member of the Food and Nutrition Board over a decade ago to help establish the RDA for vitamin D. According to Heaney, the resulting RDA of 200 IU for vitamin D was based on how much of it is needed to prevent rickets. This is troubling because vitamin D deficiency can still cause significant problems at levels that aren’t extreme enough to cause rickets. To this day, the RDA for vitamin D is still 200 IU for all people 50 years old or younger. Although it increases to 400 IU for people older than 50 and to 600 IU for people over 70, these values are still quite low.
The research used to determine vitamin D’s RDA indicates that blood levels of vitamin D in a “healthy individual” range from 20 nmol/liter to 37.5 nmol/liter. However, this range only represents the typical vitamin D level for an average person, and by today’s standards, the average person is far from being a shining image of excellent health. In fact, many experts believe that as much as 80% of the population is deficient in vitamin D. Research suggests that someone who receives adequate sun exposure will have vitamin D levels in the range of 40 nmol/liter to 60 nmol/liter. As such, the “healthy” vitamin D range that the RDA is based on would be considered by many to be deficient.
In contrast to the 200 IU RDA for vitamin D, research is showing that people who don’t receive regular sun exposure would benefit from anywhere between 1,000 IU and 5,000 IU of vitamin D3 supplementation per day. In some cases where deficiency is present, the recommendations are even higher! Although this may sound like an extreme amount of vitamin D, 1,000 IU is only 25 micrograms or 0.025 milligrams. For more information about recent research on vitamin D requirements, visit the Vitamin D Council.
What Does This Mean?
Despite the fact that many experts consider the RDA of vitamin D to be far too low, which has been the case for other RDA values as well, this is by no means justification to completely ignore RDA values and consume however much of a supplement you wish to. More than anything, it’s just another indication that you need to take responsibility and educate yourself so that you can make informed decisions about your health.
This article is part of Fight Back Fridays.
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The Vitamin D Council is awesome, isn’t it?!
I’m a bariatric post-op with significant fat malabsorption, so everything pertaining to fat stored vitamins (A, D, E, and K) is of vital importance in my world. I also have a child with an orthopedic disease (I have one, too) and it’s mind boggling the improvements we’ve both realized since making informed alterations to our Vitamin D (and interrelated and accompanying vitamins) intake. It’s such an important topic! The general public really DOES need to be educated on it!
Thanks for taking the time to share this information!
Super informative article, Vin. I was infuriated when I realized just how many of us are walking around deficient in Vitamin D. It’s so lacking in our food supply thanks to industrialization, and it’s practically impossible for us to synthesize it from the sun like we should because of our indoor lives behind glass windows and frequent showers.
Taking fermented cod liver oil (high in Vitamin D & A) has been a great boon to my personal health.
Cheers,
~KristenM
(AKA FoodRenegade)
Thanks for your comments guys!
Dina – Yes, the Vitamin D Council is great! I’ve learned a lot from their work. I’m happy to hear that vitamin D has helped to improve your quality of life!
Kristen – I am infuriated by a lot of things that result from industrialization! However, I think even the most conventional minded doctors are embracing the potential of vitamin D and awareness is spreading. Despite this, it would still be nicer to see people getting more of their vitamin D from nature rather than a pill.
Great article Vin! We hid from the sun to protect ourselves from skin cancer and we gave ourselves every other kind of cancer. Sad.
I needed this article, thanks Vin.
Don’t think this was mentioned, but we can’t get the vitamin D2 which is added to milk products confused with the D3 in certain types of fish and that our skin produces from sunlight exposure. I believe D3 is more beneficial to us, and is what helps our immune system, and has been known to *help* (i say that lightly, because we just never know, do we?) prevent memory loss, heart disease and certain forms of cancer. a lot of people are deficient that don’t even know it. It’s crazy that the dairy industry is required to add vitamin D2 to milk and it’s not even that beneficial to our bodies. It is also sad that people rely on milk products to get their vitamin D and it turns out it’s not even the right one!
Absolutely, Andrea! Thanks for adding that! I’m not certain, but I’m pretty sure that D3 is now being used in milk.
First I am so happy for your help so far. I only recently discovered your site and am learning as much as I can. Vitamin D shortages are a great conern for me. I have worked 20+ years in the last 30 years on the over night shift. Seven years ago I weighted 425 and started small changes in my eating habits and have dropped to 225. Is there anything to include with the Vitamin D for those of us whom get little exposure to sun?
Hi Merlin, thank you for your comment. I’m happy to hear that you’re learning from the site. It’s also great to hear about your very impressive weight loss. Congratulations! Keep up the good work!
Aside from relying on sun exposure for vitamin D, the alternative options that I’m aware of are seafood, butter, eggs, cod liver oil, animal fat, supplements, or even some types of tanning beds. My preference from these choices are the whole foods and maybe even cod liver oil, but diet is usually not a good enough source on it’s own and there’s also a bit of uncertainty surrounding cod liver oil.
I would choose supplements over tanning beds, but I like the idea of tanning beds utilizing the body’s natural mechanism to synthesize it’s own vitamin D.
Would it be possible for you to catch some sun either a few hours prior to or after work? That would be the ideal solution.
Thank You for the reply. Seafood, butter, and eggs are regular parts of my diet trying to get out in the sun during my days off. Right now we are down to under 10 hours a day of sun and will be decreasing for awhile. When spring returns more time out in the sun riding my bike still peddle about thanks to snow tires for my bicycle with lots of lights to be seen.
hi, new to this site and stumbled upon it as I was searching info on Vitamin D. Lots of good advice on here, thanks!
I recently was told by my doctor (whom I’d just met) that I was lacking in the “D” after my yearly physical with blood work. I’d never been checked for that before that I’m aware of and not sure why she had me do it. She’s totally into organic thinking and wanted me to take a prescription for D. I didn’t have her write one knowing I can simply buy it OTC and did so a couple of weeks later.
Here’s my issue/concern: After 3 weeks of pretty much faithfully taking a D400 iu with A on a daily basis, I have become sleepy, lacking in concentration, had diarrhea, loss of appetite, dry mouth/extreme thirst…and for a bus driver the diarrhea is most unacceptable, lol.
I talked to a school nurse about the diarrhea as I had no other “flu symptoms” and it hits rather quickly and she looked up Vitamin D (which was new in my diet) in a large pill book she owns. I hadn’t associated all these “symptoms” together and hadn’t thought too too much about any of them but they all were listed under “Over-dose/Toxicity” in the book!!!
Now, needless to say, I’m cutting back to taking ONE pill on Friday evening (in case it “hits” me again), and no more. I get intermittent times of direct sunlight and 4-5 hours a day of indirect (on the bus) daily and maybe that’s enough. I’m 48 and will most certainly have skin damage/problems as I grew up and tanned wildly BEFORE the dangers of skin cancer were an issue– now I try to limit my time but use no sunblock at all.
I’ll incorporate more tuna sandwiches into my diet (Thanks Subway!), and I eat butter and eggs. Not into seafood at all, but would be interested in anything else I should be eating/drinking more of to keep my D levels up. Any advice? Other than oil pills, lol….now pills scare me! ugh…it’s been a LONG couple of weeks.
SORRY THIS GOT SO LONG….
Hi Denise,
I’m sorry to hear about your difficulty with vitamin D. The most obvious thing to do would be to ask your doctor for an alternative. It sounds like you’ve already considered natural dietary sources for vitamin D which I think is great. Although not a popular option, organ meat is a good source of vitamin D that you didn’t mention trying.
You could also try to get more sun. As long as you don’t burn, sun exposure may be less of a cancer risk than you’ve been led to believe. I suggest reading more on the issue and making an informed decision for yourself. Dark Deception by Dr. Joseph Mercola might be a good place to start.
In regard to the safety of tanning beds, the cancer risk may be a result of the electromagnetic radiation from the magnetic ballasts that run the bulbs more so than the UV radiation.