Everyone has heard of vitamin D. Most of us know that our bodies produce vitamin D when we spend time in the sun, and that if we don’t get enough sunlight, or if for some other reason our bodies don’t produce enough vitamin D, it’s not good.

But why exactly is it bad for our bodies to not get enough vitamin D?

Vitamin D plays a critical role in calcium absorption and the body’s processes that build and strengthen bones. According to the National Institutes of Health, it also has a number of other roles, “including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation.”

All-in-all, it seems like a pretty important vitamin.

Recent Mayo Clinic research further supports that notion.

The research

Andrea Aul, a 4th-year medical student in the Mayo Clinic Alix School of Medicine is the first author of a recent article in the Journal of Pediatrics, describing the incidence of several potentially life-threatening complications of hypocalcemia (low levels of calcium), and their connection to vitamin D deficiency.

Aul’s study was population-based, using the Rochester Epidemiology Project, a medical records linkage system and long-time research collaborative based in Olmsted County, Minnesota.

The research team began with the records of 15,419 children (age 0-5), residing in Olmsted County between Jan. 1, 1996 and June 30, 2017. Of these, 1,305 were diagnosed during that time with seizures, cardiomyopathy, cardiac arrest, respiratory arrest, laryngospasm, and/or tetany. (Tetany refers to hyperexcitability of the nervous system resulting in uncontrollable muscle spasms.)

The common thread

“These life threatening conditions all could be related to hypocalcemia,” says Aul. “I was intrigued by something as common and treatable as vitamin D deficiency having such potentially devastating consequences.”

Aul and her mentors, Jason O’Grady Sr., M.D., and Tom Thacher, M.D., (the paper’s senior author) assembled a team to investigate.

They first calculated the incidence of diagnosed hypocalcemia plus a potentially life-threatening complication.

“We found that among children aged 0 to 5 years, the incidence of hypocalcemia and a potentially life-threatening complication of hypocalcemia, was 6.1 per 100,000 person-years,” says Aul.

Although this number was not extremely high, it was another number that caused the team more concern.

Of those original 1,305 babies and children with the noted serious complications, less than half (460) had their serum calcium checked within 14 days of presentation, the authors report. Of those, 85 had hypocalcemia, and when other sources of the complications were excluded, 16 children were found to have a potentially life-threatening complication due to hypocalcemia.

Hypocalcemia is easily treated, once you’ve identified the problem.

However, as the authors note, “for the majority of children with life-threatening complications of hypocalcemia, it is unknown whether vitamin D deficiency contributed to their hypocalcemia, because [it] was never measured.”

Behind the scenes

This is Aul’s first peer-reviewed publication – a key milestone for individuals pursuing a doctoral degree. At Mayo Clinic, research drives everything we do for patients, and her findings build the evidence base for informed, best practice care.

She has been interested in adding research to her portfolio since she started medical school. Her advisor Dr. O’Grady recommended her as an addition to Dr. Thacher’s team, and opportunity was born.

“My advisor, Dr. O’Grady, had already agreed to collaborate with Dr. Thacher on this project and they, along with other members of the team, welcomed me to the group,” Aul says. “In addition to the excellent mentorship opportunities through this project, I also was excited by the chance to use the Rochester Epidemiology Project to better understand our community and hopefully impact patients both locally and far away.”

Aul says that although she is just getting started in research, she knows she wants to be a pediatrician. With that career focus, she hopes to build out her expertise by conducting more pediatric-specific research. Specifically she finds population health studies — such as her current work — intriguing. “I hope to utilize the unique capabilities of the REP for conducting population-based research, however possible, in the future,” she says.

Dr. Thacher, who is a family medicine doctor and researcher at Mayo Clinic, agrees that a unique value can be found in the Rochester Epidemiology Project. “Due to comprehensive medical information on the Olmsted County population going back more than 50 years, it enables one to assess disease incidence, trends over time, and long-term outcomes of clinical conditions.”

The rest of the story

Dr. Thacher says that calcium and vitamin D testing are not part of standard newborn panels.

However, knowing that vitamin D deficiency is fairly common in general, especially among infants and new mothers, he says, “We recommend vitamin D supplementation for all infants — 400 IU daily — or high dose vitamin D supplementation of mothers — 5,000 IU daily — to fortify their breast milk, in order to prevent vitamin D deficiency in infants.”

And, even more so now that the results of this study are in, he and his colleagues recommend testing for hypocalcemia and vitamin D deficiency in children who present with symptoms of seizures, muscle spasms, heart failure, and cardiac or respiratory arrest.

Aul says their paper “illustrates that although vitamin D deficiency is potentially deadly, it is easily identifiable, treatable, and avoidable. Additionally, we recommend parents learn about sources of vitamin D—through the diet, sunlight exposure, and in certain groups, through supplementation—and have conversations with their child’s healthcare provider to ensure their child receives adequate vitamin D.”

Their paper was accompanied by an editorial written by Carol Wagner, M.D., Shawn Jenkins Children’s Hospital, Medical University of South Carolina, Charleston.

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The Mayo Clinic College of Medicine and Science includes five schools:

• Mayo Clinic Alix School of Medicine
• Mayo Clinic School of Graduate Medical Education
• Mayo Clinic School of Health Sciences
• Mayo Clinic Graduate School of Biomedical Sciences
• Mayo Clinic School of Continuous Professional Development

Tags: Andrea Aul, Center for the Science of Health Care Delivery, epidemiology, Findings, Mayo Clinic Alix School of Medicine, News, pediatric research, population health, Rochester Epidemiology Project, Tom Thacher, vitamin D