Vitamin D Deficiency Leads to Increased Intraprostatic Hormones in African American Men
Abstract
Background and Rationale: Vitamin D is known as the sunshine hormone because our skin synthesizes vitamin D during sun exposure. Vitamin D is not actually a vitamin, as it is synthesized by our bodies. The capacity to make vitamin D is lower when skin is pigmented with melanin. Thus, African Americans are disproportionately low in vitamin D compared to those of European descent, with 90% of African American men having clinical vitamin D deficiency. African American men are also at increased risk of getting prostate cancer and get prostate cancer at a younger age; moreover, the disease is more lethal. The disparity in prostate cancer in African American men is not disputable, but there are likely multiple biological contributors in addition to socioeconomic status in many cases. Vitamin D is a hormone that works in our bodies similarly to other hormones, such as testosterone and estrogen, albeit each hormone has distinct functions. Our studies have shown that low vitamin D opens an “entryway” on prostate cells to let in more vitamin D, but we only observed this in African American men. This entryway is termed megalin. Megalin is also responsible for letting testosterone and estrogen into cells. In the prostate, high levels of testosterone and estrogen are known to cause cancer. Proposal: We propose that vitamin D deficiency increases the risk for prostate cancer in African American men by increasing the amount of testosterone and estrogen within the prostate. The results of our study will conclusively demonstrate whether the prostates of African American have higher levels of testosterone and estrogen, as well as prove that megalin is the entryway responsible for this. All of the experiments utilize patient-derived specimens, stored blood, prostate tissue, and tissue-derived fresh prostate cells. Clinical Applicability: Our findings may have immediate and wide implications to the clinical concern with and management of vitamin D deficiency in African American men. Although the disparity in vitamin D deficiency in African Americans is not disputed, the clinical significance is often questioned because African American men do not have altered bone health, which is a classical symptom of vitamin D deficiency. If clinicians are aware of a direct mechanism by which these men are increasing their risk of prostate cancer, vitamin D supplementation can be strongly advised. Furthermore, there is no risk of vitamin D toxicity with standard over-the-counter supplements, as this form is the same form of vitamin D made in the skin. Our data may support that vitamin D status is not “one size fits all,” and supplementation needs vary by skin pigmentation. Health Disparity Research: A proven link between vitamin D deficiency and androgen/estrogen will be paradigm-shifting in regards to the clinical importance of vitamin D status. Moreover, if we are able to provide evidence that vitamin D deficiency alters tissue levels of hormones, this will be applicable to other hormonal cancers. For example, megalin is also present in breast cancer, and there is pronounced breast cancer disparity for African American women. Intervention and adequate vitamin D supplementation for the African American community from a young age may ultimately reduce not only prostate cancer mortality, but also other cancers and disease.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 29, 2018
- Source ID
- W81XWH1810317
Entities
People
- Larisa Nonn
Organizations
- United States Army
- University of Illinois at Chicago