GrassrootsHealth study underscores the importance of vitamin D levels of at least 40 ng/ml for cancer prevention.
ENCINITAS, CA (April 06, 2016) In a study published online today in the journal, PLOS ONE, GrassrootsHealth found an inverse association between vitamin D serum levels and all non-skin cancer incidence. The analysis included pooled data from two study cohorts of women aged 55 years and older. Those with vitamin D serum levels ≥ 40 ng/ml, had a 67% lower risk of cancer when compared with those <20 ng/ml.
The two cohorts used were the GrassrootsHealth self-subscribed population cohort (N = 1,135, median serum level = 48 ng/ml) and a randomized control trial cohort (N= 1,169, median serum level = 30 ng/ml) from a 2007 study by Lappe et al. Combining cohorts gave the study authors a wider range of serum levels and improved statistical power than available in either cohort alone. The study looked at all invasive cancers, excluding skin cancer, over a median follow-up time of 3.9 years.
“In 2006, when I wrote my research results, vitamin D dose-response curves were not well known. For my randomized control trial with over 1,000 women 55 years and older, I found an increase in prevention within the group that took vitamin D and calcium,” said Joan Lappe, Associate Dean for Research, College of Nursing at Creighton University and lead researcher on the 4-year RCT of vitamin D, calcium, and cancer used in this current study. “Findings from analysis of our data combined with data from the GrassrootsHealth cohort provides strong support for the effect of optimal serum vitamin D levels on cancer incidence. I am now even more convinced of the importance of vitamin D for cancer prevention.”
“We are no longer satisfied with research analyzed by treatment groups or treatment amounts alone,” said Carole Baggerly, Director of GrassrootsHealth. “Because we know there is a wide range of response for any given treatment amount, we are more interested in looking at achieved blood levels. The wide range of levels available in this pooled study allowed us to really see how big a difference there is between different serum levels, more so than from different treatment groups.”
“By studying epidemiological data on cancer incidence and latitude, we have long known there is a correlation between adequate vitamin D and cancer prevention,” said Cedric Garland, adjunct professor in the Department of Family Medicine and Public Health at the UC San Diego School of Medicine. “This paper shows that adequacy is a serum 25-hydroxyvitamin D level of at least 40-60 ng/ml when the purpose is cancer prevention and identifies a specific range over which changes in cancer incidence occur, specifically from 10 – 40 ng/ml.”
Vitamin D is created naturally in the skin through sun exposure and has been found to have many health benefits. Vitamin D is also available as a supplement. The findings of this study suggest that, regardless of how you get it, having a vitamin D serum level of ≥ 40 ng/ml is important for optimizing cancer prevention.
GrassrootsHealth is a nonprofit public health research organization dedicated to moving public health messages regarding vitamin D from science into practice. It has a panel of 48 senior vitamin D researchers from around the world contributing to its operations. GrassrootsHealth is currently running the D*action population intervention program to solve the vitamin D deficiency epidemic worldwide. Under the D*action umbrella, there are programs looking at the entire population as well as targeted programs for breast cancer prevention and a ‘Protect Our Children NOW!’ program to reduce the complications of vitamin D deficiency encountered during pregnancy and childhood.