Research Spotlight: Daily D Study

By Lainey Younkin, RD

While you’re still snoozing at 5:00 am, the Daily D team has already started their day collecting data with elementary and middle school students.  The Daily D study kicked off this past fall 2011, and visits to the schools are filled with pubertal status questionnaires, height and weight measurements, and skin color and blood samples.  An interview with the Project Coordinator, Elizabeth Olson, provided insight into the reasoning behind the study, specifics about the target population, and details regarding data collection.

Why was the Daily D study initiated?

Blood samples from the FIT study (John Hancock Research Center, PI Jennifer Sacheck, PhD), conducted from 2008-2011 in Somerville, found that 97% of 4th-8th graders were vitamin D insufficient during the late winter.

Vitamin D is important for bone health, muscle strength, and immunity.  Vitamin D deficiency is associated with lower HDL and elevated LDL in children and adolescents and is linked to the development of cardiovascular disease.  It is estimated that 6 million children in the U.S. are vitamin D deficient.

Vitamin D deficiency is even more common in northern latitudes, among some people with darker skin pigmentation, and in those who are overweight or obese.

The Institute of Medicine recommends 600 IU/day of vitamin D for children, but it is difficult for many children to consume this amount.  Many suggest that vitamin D supplementation might be necessary.

What is the study objective?

The overall objective is to determine the appropriate vitamin D supplementation requirements for children with various risk factors who live at northern latitudes.

Who is your target population?

The target population is 4th-8th grade children in Everett, Malden, and Somerville.  We have worked to recruit children who are racially diverse, have high obesity rates, and are disadvantaged socioeconomically.  To date, the first wave of the study has enrolled over 300 children.

What is the timeline of the study?

The study will be conducted over two, 12-month waves spanning from the fall of 2011 to the fall of 2014.  We have been and will continue to be in the schools every three months taking various measures such as height and weight, questionnaires, skin color, and blood samples.

Can you comment on the study design and the outcomes being measured?

This is a double-blind study in which participants are randomized to one of three different doses of vitamin D: 600 IU, 1000 IU, and 2000 IU.  Researchers will measure the impact of a 6-month “vitamin D intervention” on changes in vitamin D status and cardiometabolic risk factors in these children.

Tell me about the Daily D Study Team.

We have one Primary Investigator, Jennifer Sacheck, PhD and five co-investigators.  There are three fulltime staff members, including myself, who implement the study with the help of several translators, phlebotomists, and research assistants.

As the Project Coordinator, I work on the budget, logistics and planning, identifying and recruiting new communities and schools, and some data collection and management.

What goes on “behind the scenes” when you’re not out collecting data?

When we are not collecting data, we are coordinating adherence phone-calls with the participants, answering any questions, and addressing issues that come up.  Additionally, we continuously work on recruitment and retention strategies for current and future participants.  We are always researching potential communities and schools in which to implement the study.  Finally, there is a dearth of data to be entered, cleaned, and reconciled, which our core staff is always working on.

What reactions have you received from community members regarding involvement in the study?

School principals, nurses, teachers and parents have responded positively.  This is likely due to having heard about vitamin D deficiency from their doctors and/or in the news.  The schools are often proud to have their kids enrolled in the study, and parents often cite both the importance of their children’s health and aiding research as to why they enroll their children.

What do you hope to do with the results in terms of “real-world application” or public health interventions?

Results of this work will inform the development of evidence-based recommendations and guidelines regarding vitamin D supplementation to: maintain optimal vitamin D levels, reduce cardiometabolic risk, and help better understand a number of interactions between childhood obesity and Vitamin D.

*This interview was edited and condensed

*Photo courtesy of the Daily D Research Staff

Lainey is a first year Nutrition Communication student and registered dietitian.  She loves working with kids and has enjoyed being a research assistant for the Daily D study.  In addition, she has fun working at her jewelry business Stella and Dot and blogging at

The Friedman Sprout is a monthly student run newspaper that aims to serve the student population at the Friedman School of Nutrition Science and Policy, prospective students, and alumni. Our mission is to report on newsworthy information that affects the Friedman community including nutrition research, food policy, internship and volunteer opportunities, as well as school events. Our editorial slant is that of sustainability in food and nutrition.

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