Research Research GrassrootsHealth’s mission is based on research, both from the vitamin D scientist community and from our D*action cohort. Below are ten research papers published using data from our vitamin D replete community (average serum level of 44 ng/ml vs. the general population’s 25 ng/ml). For more research, you will find papers associated with every condition listed in the sidebar. Summaries Serum levels greater than 40 ng/ml are associated with > 65% lower risk of cancer Serum levels greater than or equal to 40 ng/ml decrease pregnancy comorbidities Serum levels over 40 ng/ml are associated with a 60% lower risk of type 2 diabetes 9600 IU/day vitamin D, from all sources, is necessary to get 97.5% of the world up to 40 ng/ml. Serum levels of 40-60 ng/ml may provide a significant reduction in breast cancer risk Quantifying both food and non-food sources of basal vitamin D input Serum levels from 20-100 ng/ml have no association with kidney stones Study finds basal (standard, non-supplemental) vitamin D intake approximately 2000 IU/day, not the 300 IU/day previously taught in medical school. Proof that vitamin D dosing is not the same for everyone. Serum 25-Hydroxyvitamin D Concentrations ≥40 ng/ml are Associated with >65% Lower Cancer Risk: Pooled Analysis of Randomized Trial and Prospective Cohort Study Sharon L. McDonnell, MPH et al. PLOS One April 2016 Read Paper Post-hoc analysis of vitamin D status and reduced risk of preterm birth in two vitamin D pregnancy cohorts compared with South Carolina March of Dimes 2009-2011 rates Carol Wagner, et al. Medical University of South Carolina October 2015 Read Paper Incidence rate of type 2 diabetes is >50% lower in GrassrootsHealth cohort with median serum 25-hydroxyvitamin D of 41 ng/ml than in NHANES cohort with median of 22 ng/ml Sharon L. McDonnell, MPH et al. The Journal of Steroid Biochemistry and Molecular Biology July, 2015 Read Paper Letter to Veugelers, P.J. and Ekwaru, J.P., A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D. Robert Heaney, MD et al. Nutrients March 2015 Read Paper 25(OH)D Serum Levels May Provide Additional Reduction in Breast Cancer Risk Sharon L. McDonnell, MPH et al. American Society for Nutrition, Scientific Sessions and Annual Meeting April 2014 Read Poster Quantifying the food sources of basal vitamin D input Sharon L. McDonnell, MPH et al. Journal of Steroid Biochemistry and Molecular Biology November 2013 Read Paper Quantifying the non-food sources of basal vitamin D input Sharon L. McDonnell, MPH et al. Journal of Steroid Biochemistry and Molecular Biology November 2013 Read Paper 25-Hydroxyvitamin D in the Range of 20 to 100 ng/ml and Incidence of Kidney Stones Stacie Nguyen, MPH et al. American Journal of Public Health October 2013 Read Paper All-Source Basal Vitamin D Inputs are Greater Than Previously Thought and Cutaneous Inputs are Smaller Robert P. Heaney, MD et al. The Journal of Nutrition March 2013 Read Paper Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention Cedric F. Garland, Dr PH FACE, et al. Anticancer Research 2011 Read Paper