Written by Chrystal Moulton, Staff Writer. By using a minimal blood level of 20 nanograms found that with each 50% increase in blood levels of vitamin D, there was a 20% lower risk of getting fibroid tumors.
Uterine leiomyomata also known as fibroids are a non-cancerous growth of cells in the uterine muscle. (1) Common symptoms include excessive bleeding during menstruation and severe abdominal pain. Fibroids are common among black women (2) who generally have an earlier onset (3), larger tumors, and more severe symptoms of the disease (4). Researchers have speculated that a simple nutritional deficiency may be an important factor in the development and severity of this sickness. However, there are very few studies that address this matter. (2) Furthermore, there is very little understanding of this illness since what triggers its development and growth is unknown. (5)
Vitamin D is known to control cell growth, enhance cell differentiation, and regulate biological processes especially extracellular matrix production. (6) Researchers in this study were interested in finding out if the prevalence of fibroids was related to plasma vitamin D levels in both black and white premenopausal women. (7)
A random sample of women from 1996 to 1999 underwent ultrasound screening by the National Institute of Environmental Health Sciences Uterine Study. Women who presented masses >0.5cm in diameter qualified as fibroids. Participants were 35-49 years of age and agreed to relinquish medical records as needed to establish eligibility for this study. Plasma was taken from eligible participants and a questionnaire on their exposure to sunlight was given to assess their levels of vitamin D.
Statistical methods were used to determine the association between vitamin D status and fibroids in both black and white women separately. Calculations were set to control for other risk factors believed to influence fibroid development such as the age of their first period, age, pregnancy history, body mass index (BMI), and level of physical activity. Size of fibroid in relation to plasma vitamin D status was analyzed over the entire sample. Minimally sufficient level of vitamin D in plasma was used as 20ng/ml. Incremental increases in vitamin D and prevalence of fibroids was also investigated.
A total of 1,036 women were eligible for this study. Of them, 620 were black and 416 were white. In the total sample, 80% of participants reported having at least 1 hour of sun exposure per day and only 26% had sufficient circulating vitamin D (>20ng/ml). The average vitamin D level in plasma was 14.6ng/ml ± 0.3 and levels were significantly lower in blacks (10.4ng/ml ± 0.3) than whites (20.7ng/ml ± 0.3) (p<0.001). Also, in their assessment of the relationship between levels of vitamin D and risk of fibroids, researchers found that with each 10ng/ml increase in vitamin D there was an estimated 20% lower odds of having fibroids (adjusted odds ratio [aOR]=0.80). Women who had sufficient vitamin D (>20ng/ml) showed an estimated 32% reduced odds of fibroids when compared with vitamin D deficient women (aOR=.068). Furthermore, medium to high sun exposure was associated with a 40% (aOR=0.6) reduction in the odds of fibroids relative to low sun exposure (<1 hour sun exposure). These relationships were observed in both blacks and whites.
Source: Baird, Donna Day, Michael C. Hill, Joel M. Schectman, and Bruce W. Hollis. “Vitamin D and Risk of Uterine Fibroids.” Epidemiology (Cambridge, Mass.) 24, no. 3 (2013): 447.
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Posted October 3, 2013.
Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
References:
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- Sabry M, Al-Hendy A. Innovative oral treatments of uterine leiomyoma.Obstet Gynecol Int. 2012;2012:943635.
- Laughlin SK, Baird DD, Savitz DA, Herring AH, Hartmann KE. Prevalence of uterine leiomyomas in the first trimester of pregnancy: an ultrasound-screening study. Obstet Gynecol. 2009;113:630–635.
- Kjerulff KH, Langenberg P, Seidman JD, Stolley PD, Guzinski GM. Uterineleiomyomas. Racial differences in severity, symptoms and age at diagnosis. J Reprod Med. 1996;41:483–490.
- Schwartz SM, Marshall LM, Baird DD. Epidemiologic contributions to understanding the etiology of uterine leiomyomata. Environ Health Perspect. 2000;108(suppl 5):821–827.
- Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357:266–281.
- Baird DD, Hill MC, Schectman JM, Hollis BW. Vitamin D and the Risk of Uterine Fibroids. Epidemiology. 2013;24(3):447-453.
