I have previously written about vitamin D and cancer, MS, Alzheimer’s, fetal brain development, autism, preventing fractures, and preventing falls in elderly. Studies on vitamin D in preventing heart disease have been equivocal (inconclusive or conflicting) with some studies showing benefit and others not.
In January 2014 I wrote several columns on the importance of correct study methodologies for nutrients, which are different than for drugs for a number of reasons. In his blog Dr. Cannell of the Vitamin D Council has explained the failures to find benefit with many vitamin D studies as due to poor study design. In 2005 Cannell and colleagues published a list of guidelines for vitamin D studies in order to obtain meaningful results.
The guidelines included:
• use the D3 form with daily dose of 3,000 – 10,000 IU
• ensure that blood levels reach 40-65 ng/ml in the test group, and
• run the study for at least 5 – 9 months.
Additional guidelines mentioned in his blog post:
• use subjects that are D deficient for both test and placebo groups
• test blood levels before, during, and at the end of the study
• use objective measurements of improvement.
So what happens when researchers follow these guidelines? In a June 2016 blog post Dr Cannell reported on a study by the Leeds Institute in England, published March 24 in the Journal of the American College of Cardiology, which followed their guidelines. What did they learn?
Chronic Heart Failure (CHF) is a common heart condition with a 50% five-year mortality rate. Approximately 90% of patients with CHF are vitamin D deficient. The randomized controlled study divided 223 subjects with CHF who were already on “optimal standard treatment” into a test group given 4,000 IU daily and a placebo group. The average vitamin D levels at the beginning was 10 ng/ml; the treatment group increased to an average of 46 ng/ml during the study. Small but significant improvements in cardiac function were measured in the test group for heart size and blood volume pumped by the left ventricle. The authors concluded:
“We have demonstrated that high-dose vitamin D3 supplementation is safe, well-tolerated, and associated with a clinically relevant improvement in cardiac function in CHF patients …”For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.