Vitamin D plays an integral role in bone health through multiple direct and indirect mechanisms, including the regulation of calcium and phosphate metabolism. It is also well understood that severe vitamin D deficiency is associated with rickets in children and osteomalacia in adults. However, the relationship between vitamin D and bone is not straightforward. For example, vitamin D status and bone mineral density are not well correlated, especially in some populations, and poor vitamin D status is inconsistently associated with risk of stress and other fractures.

The seemingly complicated relationship between vitamin D status and bone health may be masked by the biochemical marker commonly used to assess vitamin D status. Assessment of vitamin D status via serum total 25-hydroxyvitamin D, or 25(OH)D, testing is common among the general population and many athletic communities. For example, more than two-thirds of NCAA Division I athletic programs reported routine vitamin D testing in 2019. However, bioavailable 25(OH)D concentration may be a better indicator of vitamin D status than total 25(OH)D concentration. Bioavailable 25(OH)D is most readily available for activation and interaction with tissues via vitamin D receptors and thus may better reflect true vitamin D status. In addition, bioavailable 25(OH)D has been shown to be associated with bone mineral density, particularly in Black and African American individuals (likely due to genetic variation).

In our study, published in the March 2022 issue of Medicine & Science in Sports & Exercise_® (MSSE), we explored the utility of bioavailable 25(OH)D in our cohort of male and female NCAA Division I athletes. Similar to previous findings, including those by Allison et al. also published in MSSE, we observed no association between serum 25(OH)D concentration and total body bone mineral density. However, we did observe a moderate association between bioavailable 25(OH)D and total bone mineral density (r = 0.618).

Of the 53 athletes in our study, 74% were classified as having low vitamin D status based on total 25(OH)D concentration (< 75 nmol/L). In contrast, only 19% were classified as having low vitamin D status based on bioavailable 25(OH)D (< 5 nmol/L). Importantly, more than half of participants (32% of white and 77% of Black or African American participants) would have been classified differently based on total and bioavailable 25(OH)D concentrations. In the clinical setting, using total 25(OH)D concentrations to determine vitamin D status, which is commonplace, may be sub-optimal. One risk is overtreating with vitamin D supplements, which at higher doses could result in hypercalcemia, weakness, bone pain, kidney stones and tissue calcification, among other adverse effects. Another risk is undertreating, which may have numerous impacts to health and performance.

Sports medicine clinicians and athletes routinely base vitamin D treatment and dosing decisions on total 25(OH)D concentration. However, without knowing bioavailable 25(OH)D concentration, a big part of the complicated story is incomplete. Further research into the use of the bioavailable 25(OH)D biomarker with athletes and into the development of a commercially available bioavailable 25(OH)D assay is needed.




Michelle Rockwell Ph.D., R.D., CSSD, is an assistant professor with the Department of Family & Community Medicine at the Virginia Tech Carilion School of Medicine and an adjunct faculty member with the Department of Human Nutrition, Foods, and Exercise at Virginia Tech. Dr. Rockwell’s vitamin D research has focused on the nutrient’s role in athletic performance, the utility of the total 25(OH)D biomarker, and clinical care patterns in a variety of settings, with a particular focus on overuse. She completed dietetics training at the National Institutes of Health, earned a Ph.D. from Virginia Tech, is a certified specialist in sports dietetics, and is a member of ACSM.



Enette Larson-Meyer, Ph.D., R.D., FACSM, is a professor at Virginia Tech in the Department of Human Nutrition, Foods, and Exercise, where she directs the Nutrition and Exercise Metabolism Laboratory. Her lab has been interested in the assessment of vitamin D status and its role in the health and performance of athletes since 2010. Dr Larson-Meyer is an ACSM fellow and serves as an associate editor for MSSE. She completed her dietetic training at Massachusetts General Hospital in Boston and her doctoral/postdoctoral studies at the University of Alabama at Birmingham.

Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily represent ACSM positions or policies. Active Voice authors who have received financial or other considerations from a commercial entity associated with their topic must disclose such relationships at the time they accept an invitation to write for SMB.

Dr. Josephine Langworthy Rathbone: A Role Model for Contemporary Women in Sports Medicine

Many ACSM members have heard the name, Josephine Langworthy Rathbone, Ph.D., but do not know who she was. Dr. Rathbone was a founder of ACSM, the only woman among the group of 11. Some have suggested she was present because she was married to another founder, Dr. Peter Karpovich, whom she married in 1945 at the age of 46. Dr. Rathbone was a recognized scholar and teacher in her own right, and it is disingenuous to think that she did not “deserve” to be part of this stellar group.

Dr. Rathbone was a leader in the inception of the fields of corrective physical education, physical therapy and rehabilitation, the application of recreation to rehabilitation, health education and relaxation. Indeed, she considered herself to be both a physical therapist and physical educator. She was influential professionally and was leader in organizations besides ACSM, including the American Physiotherapy Association (now the American Physical Therapy Association) and the American Association of Health, Physical Education, Recreation, and Dance (now called Shape America). Her scholarship in the field was impactful, changing the way that disabling conditions were viewed. She wrote four widely distributed academic books that went through many editions and printings. Her work on relaxation was frequently featured in the media, and she wrote a lay book that many of us can use today, “Teach Yourself How to Relax.” In her formative work in rehabilitation, she asserted that the goal of rehabilitation was to help an individual with a disabling condition to “reach his maximal degree of physical, mental, social, vocational and economic recovery,” and she advocated for an interdisciplinary team approach to rehabilitation that spanned clinical, educational and recreational settings. Rathbone was a skilled teacher who promoted inclusion in her pioneering work in corrective physical education and her individualized approach as an educator.

“You will learn that although all men are created equal in their rights to be treated fairly by you, and by all the other forces which will enter their lives. There are others who will need a lot of help. You learn to be kind and considerate and thoughtful of their rights.” – Dr. Josephine L. Rathbone

The context of the times in which she lived help to appreciate Dr. Rathbone’s accomplishments. Josephine Langworthy Rathbone was born on June 25, 1899, in New York City and died in 1989. She lived during times filled with turmoil, violence and massive social change. During her lifetime, she experienced the 1918 Flu epidemic, two world wars, the Great Depression and the Korean and the Vietnam wars. Married women typically worked at home, and single women were found in mainly clerical, teaching and nursing positions, from which they usually were required to leave if they got married or pregnant. After the 1930s, more married women could be found in the workforce, but they still remained in a minority well into the 1960s. Dr. Rathbone was inspired to study hygiene and physical education by her high school PE Teacher, Miss Patrick, the head of the Girl’s Physical Education (PE) Department (note that PE was separated by gender until 1972 on the advent of Title IV), and her father encouraged her to select a profession related to health. Upon graduation in 1917, she entered Wellesley College, earning her B.A. in zoology in 1921, followed by a Teaching Certificate in Hygiene and PE in1922, and an M.A. in 1923. She was awarded one of the first master’s degrees in PE in the U.S.-- and the first awarded at Wellesley College. For her master’s thesis research on energy expenditure of various exercises, she was among the first outside of the military to use a Douglas Bag to collect expired air, and she analyzed the gas content using the newly invented Haldane Apparatus. After graduation, Rathbone went on to become the Director of Health at New Britain Normal School (now Central Connecticut State University) at an annual salary of $1,900. Subsequently she held appointments as Director, Corrective Physical Education at Wellesley College (1925-1930) and at Teachers College, Columbia University (1930-1960). She also was affiliated with Springfield College. While at Columbia, she earned her Ph.D., the first doctoral degree awarded in physical therapy.

Dr. Rathbone lived when participation in sports were considered “unfeminine” -- and even “dangerous” to their reproductive organs—a fallacy that endured well into the later part of the 20^th century. Until the 1930s, Dr. Rathbone and her active peers (she was a rower and referee) were constrained by having to wear special “gym” suits extending from neck to ankle, consisting of baggy long sleeved tops and bloomers, and voluminous bathing attire similarly covering most of the body. It is remarkable that women could move, no less engage in active movement and sports, but they persisted!

Dr. Rathbone navigated the prevailing gender-restricted social norms and, nonetheless, she made make an indelible impact on her profession. She was not afraid to speak up and was an advocate for her gender, although she denied being a women’s libber. At that time Columbia University denied women faculty entrance to the faculty club unless escorted by a male colleague and--even then—they had to enter through a separate women’s entrance. An anecdote tells of Dr. Rathbone breaking that rule and walking in via the main entrance along with her male colleagues. She was willing to speak up publicly; notably, she commented in the media on the exceptional contributions of women to the war efforts, countering criticisms that women were unreliable and often absent, and explaining their dual obligations of work and caring for their families for which they frequently did not have other support.

This is only a small snapshot about Dr. Rathbone—she was an amazing woman who accomplished much during her lifetime. Josephine Rathbone is someone whom all can admire for her impactful scholarly work and appreciate for laying the foundations to all who are following in her footsteps.

Each year at the ACSM Annual Meeting the Josephine L. Rathbone Memorial Breakfast Honoring Women in Leadership is held to recognize the contributions of women to the college and the fields of exercise science and sports medicine. 

 

Carol Ewing Garber, Ph.D., FACSM, is a professor in the Department of Biobehavioral Sciences and director of the Graduate Program in Applied Physiology at Teachers College, Columbia University. She served ACSM as president from 2014-2015, and was presented with ACSM's Citation Award in 2019.

International Women’s Day 2022 will be celebrated on Tuesday, March 8^th with a theme of breaking down bias, stereotypes and discrimination. The early years of exercise science and sports medicine were dominated by men, as were many of the sciences. There were, of course, exceptional early female pioneers in our discipline, including (but not limited to) women like Dr. Josephine Rathbone, Dr. Barbara Drinkwater, Dr. Charlotte Tate, and Dr. Priscilla Clarkson. These women found ways to break down stereotypes and face discrimination to achieve excellence and mentor the next generation of scientists (both male and female). I know what excellent mentorship looks like, because I was lucky enough to have been mentored by Priscilla Clarkson, Ph.D., FACSM, and I want to take this opportunity ahead of International Women's Day to highlight Dr. Clarkson’s legacy.

The most fortuitous moment in my professional life was to join the laboratory group of Dr. Clarkson in the Fall of 1999, as she had just been elected President of ACSM for 2000 (the third woman to serve in this role after Drs. Drinkwater and Tate). She spent 48 years at the University of Massachusetts Amherst, including her time as an undergraduate and graduate student. She joined the faculty in 1977, eventually rising to Distinguished Professor of Kinesiology and Dean of the Commonwealth Honors College, where she led groundbreaking educational advances until her passing in 2013. Dr. Clarkson had a lifelong passion for studying human performance, starting with her background as a ballet dancer, and evolving over time with a central theme of skeletal muscle health. She pioneered early advances in the study of muscle damage caused by intense exercise, being one of the first to describe adaptive changes we now call the “repeated bout effect.” She was also a key figure in sports nutrition and exercise metabolism research, including co-authoring several important reviews and position stands. Dr. Clarkson was never afraid to pivot into new areas of research, as I found out when we joined a genetics consortium and started doing molecular biology and genetics in the early 2000s – overhauling the entire wetlab to enable us to ask new questions about how muscle responds to exercise (and statins, atrophy, supplements, etc.). It was not uncommon for her to be the IRB chair, on the Gatorade science board, giving the Wolffe lecture and directing a ballet at the same time, all while answering every email within the hour.

I want to share a personal reflection of how Dr. Clarkson’s influence continues to impact my life. One of the benefits of serving the American College of Sports Medicine is being asked to serve in the wider scientific community. In 2013, I was asked to represent ACSM on FASEB’s Excellence in Science Award committee. This award is essentially a lifetime achievement award for women in science, and I wish everyone could read all of the amazing applications in support of women across the scientific spectrum. The Award nomination packet includes letters from colleagues and mentees, in support of lauding their outstanding female mentors. As junior faculty at the time, it was greatly inspiring to see how great mentorship by women manifested across diverse disciplines; but, for the first several years, I read many of these letters through tears, because I had one of those rare relationships and had lost it prematurely. I served on that committee for eight years, and while it became easier to read the letters, I always compared the experiences from the letters to my time with Dr. Clarkson.

Her voice is still in my head when I’m not moving fast enough, or in one of those, “What would Priscilla do?” moments (though I must draw the line at ballet dancing). Amazingly, I know more than a dozen people who had similar relationships with Dr. Clarkson – across the spectrum from undergraduate to peer mentees (formal and informal – there are always more people whose lives she touched). We are a second family – the Clarkson family – and I am sure the group text will light up with delight seeing ACSM honor her legacy on International Women's Day.

You can learn more about Dr. Clarkson's contributions to ACSM here.

Established in memory of Dr. Clarkson, the Priscilla M. Clarkson Memorial Fund provides annual assistance to help fund travel expenses accrued by one undergraduate student to present his/her scholarly work at the ACSM Annual Meeting. You can learn more and donate to the fund here.

*Above picture: Dr. Clarkson at 2010 ACSM Conference Honor Award Ceremony with former UMASS students. From left: Eric Rawson, Sandy Hsieh, Cynthia Chi, Adam Persky, Melissa Roti, Mary Miles, Priscilla Clarkson, Maria Urso, Monica Hubal, Amy Kearns, and Kimberly Reich

Monica Hubal, Ph.D., FACSM, is an associate professor in the Department of Kinesiology at Indiana University Purdue University Indianapolis (IUPUI). She currently serves ACSM as a member of the Research Review Committee, and as an associate editor of both Medicine & Science in Spirts & Exercise_® and Exercise and Sport Sciences Reviews. She was a student of Dr. Priscilla Clarkson at the University of Massachusetts Amherst.