ABSTRACT
BACKGROUND: Concentrations of vitamin D (VitD) and 25-hydroxyvitamin D (25OHD) in breastmilk are low despite the essential role of VitD for normal infant bone development, yet additional metabolic forms of vitamin D may be present. This study evaluates the contribution of sulfated vitamin D metabolites, vitamin D3-sulfate (VitD3-S) and 25-hydroxyvitamin D3-sulfate (25OHD3-S) for lactating women and assesses the response to high-dose VitD3 supplementation. METHODS: Serum and breastmilk were measured before and after 28 days with 5000 IU/day VitD3 intake in 20 lactating women. Concentrations of VitD3-S and 25OHD3-S in milk, and 25OHD2, 25OHD3, 25OHD3-S, VitD3 and VitD3-S in serum were determined by mass spectrometry. RESULTS: Baseline vitamin D status was categorized as sufficient (mean ± SD serum 25OHD3 69 ± 19 nmol/L), and both serum VitD3 and 25OHD3 increased following supplementation (p < 0.001). 25OHD3-S was 91 ± 19 nmol/L in serum and 0.47 ± 0.09 nmol/L in breastmilk. VitD3-S concentrations were 2.92 ± 0.70 nmol/L in serum and 6.4 ± 3.9 nmol/L in breastmilk. Neither sulfated metabolite significantly changed with supplementation in either serum or breastmilk. CONCLUSIONS: Sulfated vitamin D metabolites have prominent roles for women during lactation with 25OHD3-S highly abundant in serum and VitD3-S distinctly abundant in breastmilk. These data support the notion that 25OHD3-S and VitD3-S may have physiological relevance during lactation and nutritional usage for nursing infants.
ABSTRACT
Introduction: More than 50% of primary care physicians' practice involves sedentary desk work. Growing evidence suggests a link between sedentary workplace behaviors and increased morbidity and mortality. Research on the effects of sit-stand desks in the workplace suggests that sit-stand desks reduce sedentary behaviors. This study examined the use and satisfaction of adjustable desks with a height of sit-stand and their association with physical self-care behaviors among family medicine residents. Methods: We conducted a longitudinal cohort survey study at a 9-9-9 family medicine residency after the clinic installed height-adjustable sit-stand desks in January 2020. Standardized questions about the use and satisfaction of adjustable sit-stand desks and physical self-care behaviors were administered in June 2020, December 2020, and December 2021. The survey also included an open text box for feedback. Results: Median time spent standing at the sit-stand desks was 55.0%. The percentage of time standing was similar across June 2020, December 2020, and December 2021. The average satisfaction rate with the desks across all time points was 71.4%. We did not observe significant differences in the proportion of residents' satisfaction with the adjustable desks over time. Residents who reported standing at the adjustable desk reported increased satisfaction with the desks (Kendall's τ=.38, P<.001) and with physical self-care behaviors (Kendall's τ=.25, P<.05). Themes associated with desk dissatisfaction revolved around limited desktop space. Conclusion: Over a nearly 1.5-year period, more than half of family medicine residents reported standing at their adjustable desks and being satisfied with them. Residents who reported standing at adjustable desks also reported increased physical self-care behaviors. Residency programs investing in sit-stand desks may consider options that allow for increased desktop surface space.
