Vitamin D: Latest News from USANA’s R&D Team

Lisa Kuftinec Products, USANA 20 Comments

Last week, the Institute of Medicine (IOM) released a statement (PDF) that said most adults do not need to consume any more than 600 IU per day of vitamin D, which may have left you wondering why USANA recommends so much more.

To be sure, we here at USANA were happy to see their recommended intake tripled and the upper limit doubled, but in talking to Dr. John Cuomo, USANA’s Executive Director of Research and Development, he was disappointed that the IOM was so conservative, as there is a growing body of research that supports a number of protective benefits from significantly higher intakes.

Most conservative estimates have suggested that, for optimal health, blood levels of circulating vitamin D need to be above 30 ng/mL (75 nmol/L). USANA’s Research and Development (R&D) team is always looking to validate current research and explore new areas. So, they decided to look more closely into how much vitamin D most people would need to take in order to reach that level. Findings from the winter study they conducted earlier in the year are available on (PDF), and now the data is in for the summer portion of their vitamin D study. The results were pretty surprising to me, so I thought I would provide you with a recap, with the help of USANA Senior Scientist Brian Dixon, Ph.D. and Marketing Manager Camille Fletcher.

As I am sure you know, vitamin D is known as the sunshine vitamin. With the second part of the study being done in the summer, I would have thought that the vitamin D levels would have been significantly higher than in the winter study because we are outside more. Not so. In fact, the difference of average vitamin D levels was equal to consuming only 300 IU of vitamin D or increasing circulating levels by 3 ng/mL when compared to levels in winter. A pretty negligible difference, and, in USANA’s opinion, further evidence that RDAs are not nearly high enough.

Brian shared with me a variety of factors that limit the amount of vitamin D we are exposed to: where we live (geographic latitude), season, age, melanin content of skin, the use of sunscreen or sun-obscuring clothing, and a lack of outdoor activity.

Vitamin D Deficiency
Due to all of these factors, and the fact that vitamin D is unique because very little can be obtained through a normal diet, you will not be surprised to find out that more than 1 billion people worldwide and 30-40% of the U.S. population between the ages of 15-49 are vitamin D deficient.

Perception vs. reality is interesting, isn’t it?

Also of note in the second phase of the study: USANA Associates/Preferred Customers were found to have 35% higher vitamin D levels than non-USANA participants. When the data from both the summer and winter studies is combined, USANA Associates/Preferred Customers had 50% higher vitamin D levels, and were 5.5 times more likely to have optimal vitamin D levels above 30 ng/mL.

Wow — the power of USANA and vitamin D.

In light of last week’s IOM announcement, the R&D team looked again at the data. The research shows that nearly 70% of adults taking 600 IU or less of supplemental vitamin D have circulating levels below the minimum recommended threshold of 30 ng/mL. In fact, some people require up to 12 times that amount to maintain optimal levels of vitamin D. That is why USANA’s recommended daily intake of vitamin D remains at least 4,000 IU per day. Of course every person’s individual needs are different, so it is best to work with your physician to determine what is right for you.

Brian and the rest of the R&D team will be sharing their findings in scientific, peer-reviewed journals in the coming months and will continue adding to the scientific evidence that proves the importance of optimal intakes of vitamin D. Well done team!!


Comments 20

  1. I was speaking with a naturopath during the week and she was telling me that the amount of fresh veggies and fruit that are consumed influence the uptake of Vitamin D. Did the research look at people's overall diets?

  2. I think it is also important to note that the recommendations that came from IOM were based on a review of the literature rather than any actual study, meaning they are making assumptions that have not been tested or proven. Interesting that if anyone else were to make such broad statements in regards to health they would not get far.

    Thanks USANA, as always, for explaining the science.

  3. Hi Helen,
    I'll check with Brian but I believe participants answered survey questions that included questions about diet. I'll double-check.


  4. Brian & USANA R & D,

    I am so thankful to you all for helping us in the field separate the truth from the error in the media reports. Isn't it interesting that the press never seem to be in favor of dietary supplements?

    Wishing You Plenty To Live,
    Tom Doiron

  5. PROFESSOR Frank Garland, and his brother, Cedric, recommend […] taking 50,000 units of vitamin D per week for eight to twelve weeks followed by maintenance on 1,000 to 2,000 units a day”.
    ACCORDING Cedric F. Garland, Dr. P.H., FACE, Department of Family and Preventive Medicine and Moores Cancer Center of the University of California, San Diego (UCSD), “It is projected that raising the minimum year-around serum 25(OH)D level to 40-60 ng/ml (100-150 nmol/L) would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year, and three quarters of deaths from these diseases, in the US and Canada.”
    Plasma vitamin D and mortality in older men: a community-based prospective cohort study.
    “There was a U-shaped association between vitamin D concentrations and total mortality. An approximately 50% higher total mortality rate was observed among men in the lowest 10% (<46 nmol/L) and the highest in the highest 5% (>98 nmol/L [or 39 ng/ml]) of plasma 25(OH)D concentrations compared with intermediate concentrations. Both high and low concentrations of plasma 25(OH)D are associated with elevated risks of overall and cancer mortality.
    Dr. Frank C. Garland, 1950-2010
    “Tuesday, August 17 at UCSD Thornton Hospital after contending with a nearly year-long illness.“

    “African Americans … are more likely to be vitamin D deficient due to their darker skin pigmentation’s ability to block the sun’s rays”
    It is not true that melanin blocks the wavelengths which synthesize vitamin D . The value of melanin as a sunscreen (2010).
    “epidermal melanin is not a neutral density filter providing no or minimal protection for the induction of erythema at 295 and 315 nm and some protection at 305 and 365 nm”
    It does block 305nm but around that wavelength is the most damaging A UVB Wavelength Dependency for Local Suppression of Recall Immunity in Humans Demonstrates a Peak at 300 nm. also see Erythema curve. Note the relative danger curve ( yellow) peaks at around 305nm
    T the blocking of a limited spectra of vitamin D synthesizing UVB doesn’t matter the other wavelengths get through. Blood vitamin D levels in relation to genetic estimation of African ancestry “found novel evidence that the level of African ancestry [rather than skin pigmentation] may play a role in clinical vitamin D status”.
    There is a negative feedback system; evolution has has got vitamin D levels just right
    Klotho protein deficiency and aging.
    “α-Klotho protein is shown to function in the negative feedback regulation of vitamin D3 synthesis These observations indicated that abnormal vitamin D3 metabolism is the main cause of aging phenotypes.″
    Klotho was named after one of the Moirae or fates, supplementing vitamin D is indeed a fateful step.

    Many people of tropical ancestry have a optimum homeostasis of vitamin D which is below the new IoM levels, but if they're wise they'll not take supplements

  6. Dear Anonymous,

    "USANA's Vitamin D supplement is made with cholecalciferol (vitamin D3), which research suggests is better than competing forms at raising levels of vitamin D in the blood.", pages 38 & 39 of 2010-2011USANA Product Information Booklet.

    Hope this helps.

    Wishing You Plenty To Live,
    Tom Doiron

  7. Tim and Helen,

    I apologize for my slow response—I’m just back from a working trip to the Linus Pauling Institute.

    We did indeed capture dietary data during our vitamin D studies. But in an effort to get this information out as quickly as possible, we did not take dietary intake into account (to do this for almost 1,000 study participants takes a long time). And while initial analyses indicate that diet affected circulating vitamin D levels, we did not take it into account for the data listed in this blog post.

    However, by not expressing the data in that manner, we have are stating much more conservative numbers than the final data will show. That is, someone taking 600 IU of supplemental D3 (the new RDA) and not accounting for the likely couple-of-hundred IU’s contained in a diet (let’s say 500 IU for the sake of argument) would make vitamin D intake a total of 1,100 IU.

    So rather than assuming 600 IU of vitamin D yielded a circulating level of 28 ng/mL (the actual calculated number) it really took 1,100 IU to achieve the 28 ng/mL.

    So again, the way we presented the data here errs on the side of being more conservative as opposed to making grandiose, exaggerated claims to support our recommendations (and by the way, it doesn’t also take into account sun exposure which we also collected and would also likely make this data an even more conservative estimate).

    I hope that helps answer your question. And thank you everyone for your comments. It’s nice to know our Scientific Team is appreciated. Let me know if you have any other questions.

    Sincerely in health,

    Brian Dixon

  8. At Convention in Salt Lake City oneof the Doctors from Sanoviv told me that people with MS should be taking the Essentials and 5,000 – 6,000 IU every day of Vitamin D. what's your felling to that amount?
    Need to know,
    M. Rice

  9. Brian, Yes we certainly do appreciate the incredible research that all of you do at USANA to give us the highest quality products possible. We wouldn’t be as healthy without you!! I was part of the Vitamin D study both times and was quite surprised that my D levels had not risen more after a summer frequently in the sun and continuing to take approximately 3400 IU of USANA’s D3. Needless to say, this winter I have increased my daily intake to 7000. I will be interested to see what my lab reading lab is in June when I will do another blood study. Thank you again for all that you do!

  10. I have heard of people who take 5000IU of Vitamin D, specifically ones from colder states like North Dakota or Alaska. I know that is due to minimal sun exposure but how come USANA doesn’t have 5000IU in their Vitamin D.


  11. Hi,It seems everybody here is an expert of usana products. So I have a question to ask. I just start to take healthPak(only half pak each day). I find it course insomnia for me. Any explanation?

  12. Plain and simple, it comes down to serum vitamin D levels to see how deficient you are in vitamin D. Then assess how much sunlight a person is getting on average. Then what kinds of foods are they eating. With all these factors being known to increase or decrease vitamin D levels, I don’t think there can be a general number like 3,000IU of Vitamin D per day for a child between 12 months to a person of 50 years of age. Considering that Vitamin D is a fat-soluable molecule it can be toxic to individuals who don’t know this. Same goes for Vitamin A, E and K. Furthermore, high doses of vitamin D supplements coupled with large amounts of fortified foods may cause accumulations in the liver and produce signs of poisoning. Signs of vitamin D toxicity include excess calcium in the blood, slowed mental and physical growth, decreased appetite, nausea and vomiting.

    I think this study needs to look at all the factors that could potentially affect the outcome of this study, which was noted by Brian Dixon who responded to Tim and Helen’s comments. Otherwise the studies results will be extremely biased, open to random error, with low reliability and validity. Control those potential confounds that could cause low reliability.

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