Vitamin D Deficiency in Reproductive Age Mongolian Women: A Cross Sectional Study
The Journal of Steroid Biochemistry and Molecular Biology; online 27 September 2013
Davaasambuu Ganmaa gdavaasa at hsph.harvard.edu
Michael F. Holick, Janet W. Rich-Edwards, A. Lindsay Frazier, Dambadarjaa Davaalkham, Boldbaatar Ninjin, Craig Janes, Robert N. Hoover, Rebecca Troisi
- Departments of Nutrition (DG) and Epidemiology (JRE), Harvard School of Public Health, Boston, MA;
- Channing Laboratory, Department of Medicine (DG), and Connors Center for Women's Health and Gender Biology, Brigham and Women's Hospital (JRE), Harvard Medical School;
- Departments of Medicine, Physiology and Biophysics, Vitamin D, Skin and Bone Research Laboratory and Biologic Effects of Light Research Center, Boston University Medical Center (MFH);
- Department of Pediatric Oncology, Dana Farber Children's Cancer Center (ALF); Health Sciences University of Mongolia, Ulaanbaatar, Mongolia (DD, BN);
- Faculty of Health Sciences, Simon Fraser University (CJ); Division of Cancer Epidemiology and Genetics, National Cancer Institute, U.S. Department of Health and Human Services (RNH, RT)
Highlights
- We reported vitamin D levels in two populations of healthy Mongolian women: urban born and rural born.
- We documented lowest vitamin D levels in the world.
- We also showed severe prevalence of vitamin D deficiency.
- No vitamin D fortified and/or vitamin D rich food available in the country.
- Actions to improve vitamin D levels are required in this specific population.
Vitamin D production is critical not only for rickets prevention but for its role in several chronic diseases of adulthood. Maternal vitamin D status also has consequences for the developing fetus.
This study assessed the prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] < 20 ng/ml) and insufficiency [25(OH)D = 20-29 ng/ml] in spring, among reproductive age Mongolian women.
Blood was drawn in March and April, 2009 from 420 Mongolian women, 18–44 years of age. Serum 25(OH)D concentrations were measured, anthropometric measurements were performed and information was collected by interview on lifestyle, dietary and reproductive factors. Logarithm-transformed 25(OH)D levels were compared across risk factor categories by analysis of variance. Linear regression analysis was used to assess the independent associations of factors with vitamin D status. Cutaneous vitamin D3 synthesis was assessed between December and July using a standard 7-dehydrocholesterol ampoule model.
The vast majority of women 415 (98.8%) had serum 25(OH)D <20 ng/ml (50 nmol/l) with an additional 4 women (<1%) in the insufficient range (20-29 ng/ml); only one women (0.2%) had sufficient levels (>30 ng/ml or 75 nmol/l). 25(OH)D concentrations were positively and independently associated with educational status and use of vitamin D supplements, but not with other demographic, lifestyle, reproductive, or anthropometric factors. 25(OH)D levels were not associated with dietary factors in this population, as there is little access to foods containing vitamin D in Mongolia. No production of previtamin D3 was observed until March and was maximally effective in April and was sustained through July.
These data suggest that the prevalence of vitamin D deficiency in spring among reproductive age women in Mongolia is high. Given the lack of naturally vitamin D-rich food in the diet and limited use of vitamin D supplements, food fortification and/or supplementation with vitamin D should be considered among these women.
Perfect storm of problems in Mongolia make for extreme deficiency
- Dark skin
- No vitamin D fortifiction of foods
- No local foods with vitamin D
- No vitamin D supplements
- Extremely cold climate - so little skin exposed to the sun (average temperature year-round is 32 degrees F in their capital)
Thus Mongolia, not surprisingly, has the highest rate of rickets in the world: approx 60% of all infants.
How did Mongolians exist for such a long time?
They most likely used to have OK levels of vitamin D
They used to have their animals out of doors getting vitamin D.
Then, when they ate the pigs, etc. they got their vitamin D
See also VitaminDWiki
- Rickets in Mongolia - July 2013
- Rickets – 1 in 10,000 in Canada and UK, 1 in 2 in Russia and Mongolia
- Overview of Rickets and Vitamin D
- Group is giving only 200 IU of Vitamin D to 70 million women and children to prevent Rickets
- Percent of population with less than 20 ng of vitamin D 98% in Mongolia < 20 ng