By Greg Arnold, DC, CSCS, October 12, 2009, abstracted from “Low serum 25-hydroxyvitamin D concentrations are associated with greater all-cause mortality in older community-dwelling women” in the August 2009 issue of Nutrition Research

Research has shown a number of health benefits of vitamin D that include heart health during weight loss (1), weight and bone health (2), and breast health (3). Despite these findings, a 2009 study (4) showed that the average blood level of vitamin D in Americans dropped by 20% between 1994 and 2004 (30 nanograms/milliliter in 1994 to 24 ng/mL in 2004).  The National Academy of Sciences places the upper limit of vitamin D supplementation per day at 2,000 IU per day (5) even through 4,000 IU per day of vitamin D has been shown to be safe (6).

Now a new study (7) has found that vitamin D deficiency can significantly affect health in older women.  In the study, researchers looked at the vitamin D blood levels of 714 women between the age of 70 and 79 in the Women’s Health and Aging Studies I and II (8) and followed them for 6 years.

At the end of 6 years of follow-up, the researchers found that women in the lowest 25% blood levels of vitamin D (15.3 nanograms/milliliter)) had a 145% increased risk of death compared to women in the highest 25% of vitamin D blood levels (27.0 ng/mL ).  Although there is no formal consensus on the optimal levels of vitamin D, vitamin D deficiency is often defined as a blood levels below 20 ng/mL (equal to 50 nmol/L) (9), of which half of the women in the present study were shown to be deficient.

For the researchers, “Older community-dwelling women with low 25 (OH)D levels are at an increased risk of death.”

Greg Arnold is a Chiropractic Physician practicing in Danville, CA.  You can contact Dr. Arnold directly by emailing him at mailto:PitchingDoc@msn.com or visiting his web site at www.CompleteChiropracticHealthcare.com

Reference:

1. Zittermann A. Vitamin D supplementation enhances the beneficial effects of weight loss on cardiovascular disease risk markers. Am J Clin Nutr 2009 89: 1321-1327. First published online March 25, 2009; doi:10.3945/ajcn.2008.27004
2. Kremer R. Vitamin D Status and its Relationship to Body Fat, Final Height and Peak Bone Mass in Young Women. Jou Clin Endocrinol Metab 2008. First published ahead of print November 4, 2008 as doi:10.1210/jc.2008-1575
3. Prognostic Effects of 25-Hydroxyvitamin D Levels in Early Breast Cancer. Journal of Clinical Oncology, Vol 27, No 23 (August 10), 2009: pp. 3757-3763
4. Ginde et al. Demographic Differences and Trends of Vitamin D Insufficiency in the US Population, 1988-2004. Archives of Internal Medicine, 2009; 169 (6): 626
5. National Academy of Sciences–Institute of Medicine–Food and Nutrition Board. Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and Fluoride.
6. Basile LA, Taylor SN, Wagner CL, Horst RL, Hollis BW. The effect of high-dose vitamin D supplementation on serum vitamin D levels and milk calcium concentration in lactating women and their infants. Breastfeed Med. 2006;1:27–35
7. Semba RD.  Low serum 25-hydroxyvitamin D concentrations are associated with greater all-cause mortality in older community-dwelling women.  Nutrition Research 2009; 29(8): 525-530
8. Women’s Health and Aging Study Details available at www.nia.nih.gov/HealthInformation/Publications/Reports/WomensHealthAgingStudy.htm
9. Holick MF. Vitamin D deficiency. N Engl J Med 2007;357:266-81.