When Is it Appropriate to Use Vitamin D Supplementation?

%jwplayer%

The MD Magazine Peer Exchange “Amassing the Clinical Evidence for Optimized Dyslipidemia Management: Vitamin D, Long-Term Statin Outcomes, and PCSK9 Inhibition” features expert insight and analysis of the latest information on managing hypertension and hyperlipidemia, and in-depth discussion on the use of PCSK9 inhibitors in practice.

This Peer Exchange is moderated by Peter Salgo, MD, professor of medicine and anesthesiology at Columbia University and an associate director of surgical intensive care at the New York-Presbyterian Hospital in New York City.

The panelists are:

• Christie Ballantyne, MD, Co-director of the Lipid Metabolism and Atherosclerosis Clinic at The Methodist Hospital, Director of the Center for Cardiovascular Disease Prevention at the Methodist DeBakey Heart Center, and the Chief of Cardiology at Baylor College of Medicine
• Keith C. Ferdinand, MD, Immediate Past Chair of the National Forum for Heart Disease and Stroke Prevention, and Professor of Clinical Medicine at the Heart and Vascular Institute at Tulane University School of Medicine
• Jennifer G. Robinson, MD, MPH, Professor in the Departments of Epidemiology & Medicine and Director of the Prevention Intervention Center, Department of Epidemiology at the College of Public Health, University of Iowa
• Karol E. Watson, MD, PhD, Professor of Medicine and Cardiology, Co-director of the UCLA Program in Preventive Cardiology, and Director of the UCLA Barbra Streisand Women’s Heart Health Program

In this segment of the Peer Exchange, the panelists discuss whether the available evidence supports the use of vitamin D supplementation in preventing cardiovascular disease.

Continuing on the topic of the usefulness of vitamin D supplementation in the management of various cardiovascular conditions, Dr. Ferdinand said that there is some data that suggest patients who have low levels of vitamin D and statin intolerance may improve with vitamin D supplementation, though he said the data is somewhat less than rigorous.

He said an ideal study to examine this question would one that enrolled patients with low vitamin D levels and uncontrolled hypertension and treated them with vitamin D supplementation. Such a study would be useful he said because then you would be studying a disease “that has measurable outcomes ‑‑ strokes, heart attacks, heart failure, kidney disease ‑‑ and you would have a marker of low levels of a substance that you then replace to an adequate level” and measure the effect (if any) on that biomarker.

The panelists then spoke about what might constitute the “proper” level of vitamin D supplementation, especially in the lack of hard evidence of efficacy for prevention of cardiovascular events. Dr. Robinson said there is some concern that physicians are prescribing a pill when “when we should just be telling people go take a walk outside for 15 minutes every day” to get some sun.

Dr. Ferdinand said there is even some evidence that too much vitamin D can be harmful, noting a Danish cohort study involving more than 200,000 people that showed very high levels of vitamin D may actually have a deleterious effect. “So I’m not saying everyone should take vitamin D. I’m certainly not saying that we should supplement them ad lib until some of the data is finalized,” but it may be appropriate “in selected patients, especially darker skinned people living in northern latitudes,” he said.

Dr. Watson agreed, saying “What Dr. Ferdinand says is exactly right. The observational data really does have sort of a u-shaped distribution. Increased risk at very low levels, increased risk at very high levels as well.”

Dr. Robinson said she views low vitamin D levels as “a marker of poor lifestyle,” and often tells her patients to go out and take a 15 minute walk in the sun without sunscreen. She said she also looks at other interventions (such as the DASH diet) that can have beneficial cardiovascular effects such as lower blood pressure. “We ought to focus on lifestyle rather than just giving them a pill,” she said.

Hypertension is a powerful risk factor, maybe the most powerful risk factor for cardiovascular outcomes, according to Dr. Ferdinand. “If you look at the worldwide burden of cardiovascular disease ‑‑ including heart attacks and strokes ‑‑ hypertension may be the biggest driver,” he said.