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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Are vitamin D supplement needs similar in Caucasian & African American women?

The absorption and metabolism of vitamin D is comparable among Caucasian and African American women, according to new research published in the Journal of Clinical Endocrinology & Metabolism.

There is a well known disparity gap in vitamin D levels between different ethnicities. For example, in a CDC report last year, 65% of African Americans were deficient in vitamin D compared to just 20% of Caucasians. While it is presumed that skin color plays the largest and perhaps sole hand in this gap (the darker the skin, the more sun exposure needed to make vitamin D), researchers still wanted to know, might different ethnicities absorb or metabolize vitamin D differently?

If so, there would be big implications in setting recommended daily allowances in the future.

In this study, Professor J Christopher Gallagher, MD, from Creighton University School of Medicine in Omaha, Nebraska, and colleagues investigated this topic.

They measured vitamin D levels in 110 post-menopausal African American women aged 57-90 with vitamin D levels of 20 ng/ml or less. The women were randomized to receive a placebo or vitamin D supplement at 1 of 8 dose levels, ranging from 400 IU to 4,800 IU, for 1 year.

The authors compared the results of the present study with a parallel study examining vitamin D metabolism in Caucasian women. Vitamin D status at baseline was lower in the African American participants compared to the Caucasian participants (13 ng/ml vs 17 ng/ml respectively). They found that the increase in serum vitamin D after supplementation in African American women was similar to that seen in the Caucasian women.

Furthermore, 97.5% of women on 800 IU/daily – the RDA set by the IOM for elderly – from both the African American and Caucasian groups reached a level of 20 ng/ml.

The researchers did not report what dose it took for the African American women to reach a level of 30 ng/ml and how that compared to the Caucasian women. It is reasonable to assume that since African Americans had lower baseline levels, that they would need a bigger dose than Caucasian women to ensure 97.5% of the population reached a 30 ng/ml threshold.

However, for the time being, it looks as though vitamin D is absorbed and metabolized the same in both Caucasians and African Americans.

The authors conclude,

“The implication therefore is that the absorption and metabolism of vitamin D are similar in African American and Caucasian women. Although serum levels of serum 25OHD are usually much lower in African Americans, it is most likely because of decreased formation of vitamin D in skin.”


Gallagher JC, Peacock M, Yalamanchili V, Smith LM. Effects of vitamin D supplementation in older African American women. J Clin Endocrin Metab. February 5, 2013.

  About: Kate Saley

Kate was the Community Coordinator for the Vitamin D Council between 2012-2013. She oversaw the Council’s social media, blog, newsletter and membership base. Kate is currently going to school for occupational therapy.

3 Responses to Are vitamin D supplement needs similar in Caucasian & African American women?

  1. Rita and Misty says:


    Thank you for posting on this very important issue!

    I’ve commented before regarding Vitamin D deficiency within the African American population being a very serious problem.


    We in the Vitamin D Community know that recent research indicates that Vitamin D’s role in the body extends far greater than simply the prevention of rickets, osteomalacia and osteoporosis. Achieving and maintaining an adequate 25(OH)D level is essential to the prevention and treatment of autoimmune diseases such as MS and type 1 diabetes.

    Vitamin D also plays a protective role in cardiovascular health, various types of cancer, autism, depression, and schizophrenia, and respiratory conditions such as cystic fibrosis. The number of health conditions positively influenced by maintaining adequate levels of Vitamin D seems to increase daily.

    Because of our indoor lifestyles, Vitamin D deficiency is at epidemic proportions in the United States…actually worldwide. And it is worse among those with darker skin pigmentation, as melanin factors greatly into Vitamin D production.

    As I have mentioned before: the sunlight needs for people with darker skin pigmentation, living at higher latitudes, are immense and are not being met.

    A lighter pigmented person standing in full sun can produce a day’s bodily requirement of Vitamin D in about 15 minutes. In stark contrast, a person with darker skin pigmentation, standing in the same spot, will need approximately 6 times more sun exposure to produce the same amount of vitamin D. The following link will provide you with a thorough explanation:


    According to reports by the United States Center for Disease Control and Prevention, African American suffer greatly from chronic diseases such as cancer, heart disease, fibromyalgia, lupus, and obesity which can be effectively controlled or prevented with vitamin D supplementation.

    Unfortunately, many African Americans do not know about the health enhancing properties of vitamin D so their health continues to deteriorate.

    Despite the alarming health situation for Blacks, conventional medical practitioners do not seem to be informing Black people that they may need to take at least 5,000 IU of vitamin D3, in supplement form, every day; and that Black children should also be given adequate amounts of vitamin D3 on a daily basis, because food and drinks do not supply adequate amounts of vitamin D.

    Instead, all of us continue to be overloaded with prescription medications that treat the symptoms of illnesses while the causative factors are left unaddressed.

    Certainly Vitamin D deficiency is a serious problem for all of us…a pandemic…however, those with skin level VI have even greater deficiencies currently…and as informed members of the Vitamin D Community we have a responsibility to outreach and the time is now.

    Here you will find additional information:

    “…researchers Alan Peiris of East Tennessee State University and William Grant of the Sunlight, Nutrition and Health Research Center in San Francisco set out to look for a correlation between vitamin D and cancer death disparities. (In past research, Grant and a colleague suggested low levels of ultraviolet-B rays in Austria, paired with Mozart’s nocturnal habits, may have led to vitamin D deficiency in the composer, who died at the age of 35.)
    What they found in the new study is preliminary but warrants further investigation, they said. Relying solely on a scientific literature review, the researchers found that low vitamin D is independently associated with each of the cancer types for which an unexplained health disparity exists between African-Americans and white Americans.
    Specifically, they found lingering disparities for 13 types of cancer after accounting for socioeconomic status, stage at diagnosis, and treatment: bladder, breast, colon, endometrial, lung, ovarian, pancreatic, prostate, rectal, testicular, and vaginal cancer; Hodgkin’s lymphoma; and melanoma. For each one, there is a vitamin-D connection.
    Few scientific studies have directly explored the link between cancer deaths and low vitamin D levels in African-Americans, though. One study published in the journal Cancer in 2011 indeed found that vitamin D deficiency contributes to excess African-American mortality from colon cancer. A Harvard study published in Cancer Epidemiology, Biomarkers and Prevention in 2006 found that African-Americans who are at risk for low vitamin D also had a higher risk for cancer death, particularly for digestive-system cancers.
    The paucity of studies makes this a ripe topic for exploration, said Grant. If low vitamin D is the cause of this disparity in cancer deaths, thousands of lives could be saved annually by encouraging African-Americans to take a daily vitamin D supplement in the range of 1,000 to 4,000 IUs, he said.”




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  2. Kate Saley says:

    Thanks for the summary and links! Appreciate the additional info.

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  3. Rita and Misty says:

    To sunnier days, Kate!

    Together, I do believe we can make excellent progress in ending this pandemic.


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