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Study Overview
Objective. To test the effect of 12 months of vitamin D supplementation on lower-extremity power and function in older community-dwelling adults screened for low serum 25-hydroxyvitamin D (25(OH)D).
Design. A single-center, double-blind, randomized placebo-controlled study in which participants were assigned to 800 IU of vitamin D3 supplementation or placebo daily and were followed over a total period of 12 months.
Setting and participants. A total of 100 community-dwelling men and women aged ≥ 60 years with serum 25(OH)D ≤ 20 ng/mL at screening participated. Participants were prescreened by phone, and were excluded if they met any of the following exclusion criteria: vitamin D supplement use > 600 IU/day (for age 60-70 years) or > 800 IU/day (for age ≥ 71 years); vitamin D injection within the previous 3 months; > 2 falls or 1 fall with injury in past year; use of cane, walker, or other indoor walking aid; history of kidney stones within past 3 years; hypercalcemia (serum calcium > 10.8 mg/dL); renal dysfunction (glomerular filtration rate, < 30 mL/min); history of liver disease, sarcoidosis, lymphoma, dysphagia, or other gastrointestinal disorder; neuromuscular disorder affecting lower-extremity function; hip replacement within the past year; cancer treatment in the past 3 years; treatment with thiazide diuretics > 37.5 mg, teriparatide, denosumab, or bisphosphonates within the past 2 years; oral steroids (for > 3 weeks in the past 6 months); and use of fat malabsorption products or anticonvulsive therapy.
Main outcome measures. The primary outcome was leg extensor power assessed using a computer-interfaced bilateral Keiser pneumatic leg press. Secondary outcomes to measure physical function included: (1) backward tandem walk test (which is an indicator of balance and postural control during movement1); (2) Short Physical Performance Battery (SPPB) testing, which includes a balance assessment (ability to stand with feet positioned normally, semi-tandem, and tandem for 10s), a timed 4-m walk, and a chair stand test (time to complete 5 repeated chair stands); (3) stair climbing (ie, time to climb 10 steps, as a measure of knee extensor strength and functional capacity); and (4) handgrip strength (using a dynamometer). Lean tissue mass was assessed by dual X-ray absorptiometry (DEXA scan). Finally, other measures included serum total 25(OH)D levels measured at baseline, 4, 8, and 12 months, as well as 24-hour urine collection for urea-nitrogen and creatinine measurements.
Main results. Of the 2289 individuals screened for the study, 100 met eligibility criteria and underwent randomization to receive either 800 IU vitamin D supplementation daily (n = 49) or placebo (n = 51). Three patients (2 in vitamin D group and 1 in placebo group) were lost to follow up. The mean age of all participants was 69.6 ± 6.9 years. In the vitamin D group versus the control group, respectively, the percent male: female ratio was 66:34 versus 63:37, and percent Caucasian was 75% versus 82%. Mean body mass index was 28.2 ± 7.0 and mean serum 25(OH)D was 20.2 ± 6.7 ng/mL. At the end of the study (12 months), 70% of participants given vitamin D supplementation had 25(OH)D levels ≥ 30 ng/mL and all participants had levels ≥ 20 ng/mL. In the placebo group, the serum 25(OH)D level was ≥ 20 ng/mL in 54% and ≥ 30 ng/mL in 6%. The mean serum 25(OH)D level increased to 32.5 ± 5.1 ng/mL in the vitamin D–supplemented group, but no significant change was found in the placebo group (treatment × time, P < 0.001). Overall, the serum 1,25 (OH)2D3 levels did not differ between the 2 groups over the intervention period (time, P = 0.49; treatment × time, P = 0.27). Dietary intake of vitamin D, calcium, nitrogen, and protein did not differ or change over time between the 2 groups. The change in leg press power, function, and strength did not differ between the groups over 12 months (all treatment × time, P values ≥ 0.60). A total of 27 falls were reported (14 in vitamin D versus 9 in control group), of which 9 were associated with injuries. There was no significant change in lean body mass at the end of the study period in either group (treatment × time, P = 0.98).
Conclusion. In community-dwelling older adults with vitamin D deficiency (≤ 20 ng/mL), 12-month daily supplementation with 800 IU of vitamin D3 resulted in sufficient increases in serum 25(OH)D levels, but did not improve lower-extremity power, strength, or lean mass.
Commentary
Vitamin D deficiency is common in older adults (prevalence of about 41% in US adults ≥ 65 years old, according to Forrest et al2) and is likely due to dietary deficiency, reduced sun exposure (lifestyle), and decreased intestinal calcium absorption. As such, vitamin D deficiency has historically been a topic of debate and of interest in geriatric medicine, as it relates to muscle weakness, which in turn leads to increased susceptibility to falls.3 Interestingly, vitamin D receptors are expressed in human skeletal muscle,4 and in one study, 3-month supplementation of vitamin D led to an increase in type II skeletal muscle fibers in older women.5 Similarly, results from a meta-analysis of 5 randomized controlled trials (RCTs)6 showed that vitamin D supplementation may reduce fall risk in older adults by 22% (corrected odds ratio, 0.78; 95% confidence interval, 0.64-0.92). Thus, in keeping with this general theme of vitamin D supplementation yielding beneficial effects in clinical outcomes, clinicians have long accepted and practiced routine vitamin D supplementation in caring for older adults.
In more recent years, the role of vitamin D supplementation in primary care has become controversial,7 as observed in a recent paradigm shift of moving away from routine supplementation for fall and fracture prevention in clinical practice.8 In a recent meta-analysis of 33 RCTs in older community-dwelling adults, supplementation with vitamin D with or without calcium did not result in a reduction of hip fracture or total number of fractures.9 Moreover, the United States Preventive Services Task Force (USPSTF) recently published updated recommendations on the use of vitamin D supplementation for primary prevention of fractures10 and prevention of falls11 in community-dwelling adults. In these updated recommendations, the USPSTF indicated that insufficient evidence exists to re
Vitamin D supplementation is no longer routinely recommended for fall and fracture prevention. However, if we believe that poor lower extremity muscle strength is a risk factor for falls,12 then the question of whether vitamin D has a beneficial role in improving lower extremity strength in older adults needs to be addressed. Results regarding the effect of vitamin D supplementation on muscle function have so far been mixed. For example, in a randomized, double-blinded, placebo-controlled trial of 160 postmenopausal women with low vitamin D level (< 20 ng/mL), vitamin D3 supplementation at 1000 IU/day for 9 months showed a significant increase in lower extremity muscle strength.13 However, in another randomized double-blinded, placebo-controlled trial of 130 men aged 65 to 90 years with low vitamin D level (< 30 ng/mL) and an SPPB score of ≤ 9 (mild-moderate limitation in mobility), daily supplementation with 4000 IU of vitamin D3 for 9 months did not result in improved SPPB score or gait speed.14 In the study reported by Shea et al, the authors showed that 800 IU of daily vitamin D supplementation (consistent with the Institute of Medicine [IOM] recommendations for older adults15) in community-dwelling older adults with vitamin D deficiency (< 20 ng/mL) did not improve lower extremity muscle strength. This finding is significant in that it adds further evidence to support the rationale against using vitamin D supplementation for the sole purpose of improving lower extremity muscle function in older adults with vitamin D deficiency.
Valuable strengths of this study include its randomized, double-blinded, placebo-controlled trial design testing the IOM recommended dose of daily vitamin D supplementation for older adults. In addition, compared to some of the prior studies mentioned above, the study population included both males and females, although the final study population resulted in some gender bias (with male predominance). Moreover, participants were followed for a sufficient amount of time (1 year), with an excellent adherence rate (only 3 were lost to follow-up) and with corresponding improvement in vitamin D levels. Finally, the use of SPPB as a readout for primary outcome should also be commended, as this assessment is a well-validated method for measuring lower extremity function with scaled scores that predict poor outcomes.16 However, some limitations include the aforementioned predominance of male participants and Caucasian race in both intervention and control groups, as well as discrepancies between the measurement methods for serum vitamin D levels (ie, finger-stick cards versus clinical lab measurement) that may have underestimated the actual serum 25(OH)D levels.
Applications for Clinical Practice
While the null findings from the Shea and colleagues study are applicable to healthier community-dwelling older adults, they may not be generalizable to the care of more frail older patients due to their increased risks for falls and high vulnerability to adverse outcomes. Thus, further studies that account for baseline sarcopenia, frailty, and other fall-risk factors (eg, polypharmacy) are needed to better evaluate the value of vitamin D supplementation in this most vulnerable population.
— Caroline Park, MD, PhD, and Fred Ko, MD
Icahn School of Medicine at Mount Sinai, New York, NY
1. Husu P, Suni J, Pasanen M, Miilunpalo S. Health-related fitness tests as predictors of difficulties in long-distance walking among high-functioning older adults. Aging Clin Exp Res. 2007;19:444-450.
2. Forrest KYZ, Stuhldreher WL. Prevalence and correlates of vitamin D deficiency in US adults. Nutr Res. 2011;31:48-54.
3. Bischoff-Ferrari HA, Giovannucci E, Willett WC, et al. Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes. Am J Clin Nutr. 2006;84:1253.
4. Simpson RU, Thomas GA, Arnold AJ. Identification of 1,25-dihydroxyvitamin-D3 receptors and activities in muscle. J Biol Chem. 1985;260:8882-8891.
5. Sorensen OH, Lund BI, Saltin B, et al. Myopathy in bone loss ofaging - improvement by treatment with 1alpha-hydroxycholecalciferol and calcium. Clinical Science. 1979;56:157-161.
6. Bischoff-Ferrari HA, Dawson-Hughes B, Willett WC, et al. Effect of vitamin D on falls - A meta-analysis. JAMA. 2004;291:1999-2006.
7. Lewis JR SM, Daly RM. The vitamin D and calcium controversy: an update. Curr Opin Rheumatol. 2019;31:91-97.
8. Schwenk T. No value for routine vitamin D supplementation. NEJM Journal Watch. December 26, 2018.
9. Zhao JG, Zeng XT, Wang J, Liu L. Association between calcium or vitamin D supplementation and fracture incidence in community-dwelling older adults: a systematic review and meta-analysis. JAMA. 2017;318:2466-2482.
10. Grossman DC, Curry SJ, Owens DK, et al. Vitamin D, calcium, or combined supplementation for the primary prevention of fractures in community-dwelling adults US Preventive Services Task Force Recommendation Statement. JAMA. 2018;319:1592-1599.
11. Grossman DC, Curry SJ, Owens DK, et al. Interventions to prevent falls in community-dwelling older adults US Preventive Services Task Force Recommendation Statement. JAMA. 2018;319:1696-1704.
12. Tinetti ME, Speechley M, Ginter SF. Risk-factors for falls among elderly persons living in the community. N Engl J Med. 1988;319:1701-1707.
13. Cangussu LM, Nahas-Neto J, Orsatti CL, et al. Effect of vitamin D supplementation alone on muscle function in postmenopausal women: a randomized, double-blind, placebo-controlled clinical trial. Osteoporos Int. 2015;26:2413-2421.
14. Levis S, Gomez-Marin O. Vitamin D and physical function in sedentary older men. J Am Geriatr Soc. 2017;65:323-331.
15. Ross CA TC, Yaktine AL, Del Valle HB. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium. National Academies Press. 2011.
16. Guralnik JM, Ferrucci L, Simonsick EM, et al. Lower-extremity function in persons over the age of 70 years as a predictor of subsequent disability. N Engl J Med. 1995;332:556-561
Study Overview
Objective. To test the effect of 12 months of vitamin D supplementation on lower-extremity power and function in older community-dwelling adults screened for low serum 25-hydroxyvitamin D (25(OH)D).
Design. A single-center, double-blind, randomized placebo-controlled study in which participants were assigned to 800 IU of vitamin D3 supplementation or placebo daily and were followed over a total period of 12 months.
Setting and participants. A total of 100 community-dwelling men and women aged ≥ 60 years with serum 25(OH)D ≤ 20 ng/mL at screening participated. Participants were prescreened by phone, and were excluded if they met any of the following exclusion criteria: vitamin D supplement use > 600 IU/day (for age 60-70 years) or > 800 IU/day (for age ≥ 71 years); vitamin D injection within the previous 3 months; > 2 falls or 1 fall with injury in past year; use of cane, walker, or other indoor walking aid; history of kidney stones within past 3 years; hypercalcemia (serum calcium > 10.8 mg/dL); renal dysfunction (glomerular filtration rate, < 30 mL/min); history of liver disease, sarcoidosis, lymphoma, dysphagia, or other gastrointestinal disorder; neuromuscular disorder affecting lower-extremity function; hip replacement within the past year; cancer treatment in the past 3 years; treatment with thiazide diuretics > 37.5 mg, teriparatide, denosumab, or bisphosphonates within the past 2 years; oral steroids (for > 3 weeks in the past 6 months); and use of fat malabsorption products or anticonvulsive therapy.
Main outcome measures. The primary outcome was leg extensor power assessed using a computer-interfaced bilateral Keiser pneumatic leg press. Secondary outcomes to measure physical function included: (1) backward tandem walk test (which is an indicator of balance and postural control during movement1); (2) Short Physical Performance Battery (SPPB) testing, which includes a balance assessment (ability to stand with feet positioned normally, semi-tandem, and tandem for 10s), a timed 4-m walk, and a chair stand test (time to complete 5 repeated chair stands); (3) stair climbing (ie, time to climb 10 steps, as a measure of knee extensor strength and functional capacity); and (4) handgrip strength (using a dynamometer). Lean tissue mass was assessed by dual X-ray absorptiometry (DEXA scan). Finally, other measures included serum total 25(OH)D levels measured at baseline, 4, 8, and 12 months, as well as 24-hour urine collection for urea-nitrogen and creatinine measurements.
Main results. Of the 2289 individuals screened for the study, 100 met eligibility criteria and underwent randomization to receive either 800 IU vitamin D supplementation daily (n = 49) or placebo (n = 51). Three patients (2 in vitamin D group and 1 in placebo group) were lost to follow up. The mean age of all participants was 69.6 ± 6.9 years. In the vitamin D group versus the control group, respectively, the percent male: female ratio was 66:34 versus 63:37, and percent Caucasian was 75% versus 82%. Mean body mass index was 28.2 ± 7.0 and mean serum 25(OH)D was 20.2 ± 6.7 ng/mL. At the end of the study (12 months), 70% of participants given vitamin D supplementation had 25(OH)D levels ≥ 30 ng/mL and all participants had levels ≥ 20 ng/mL. In the placebo group, the serum 25(OH)D level was ≥ 20 ng/mL in 54% and ≥ 30 ng/mL in 6%. The mean serum 25(OH)D level increased to 32.5 ± 5.1 ng/mL in the vitamin D–supplemented group, but no significant change was found in the placebo group (treatment × time, P < 0.001). Overall, the serum 1,25 (OH)2D3 levels did not differ between the 2 groups over the intervention period (time, P = 0.49; treatment × time, P = 0.27). Dietary intake of vitamin D, calcium, nitrogen, and protein did not differ or change over time between the 2 groups. The change in leg press power, function, and strength did not differ between the groups over 12 months (all treatment × time, P values ≥ 0.60). A total of 27 falls were reported (14 in vitamin D versus 9 in control group), of which 9 were associated with injuries. There was no significant change in lean body mass at the end of the study period in either group (treatment × time, P = 0.98).
Conclusion. In community-dwelling older adults with vitamin D deficiency (≤ 20 ng/mL), 12-month daily supplementation with 800 IU of vitamin D3 resulted in sufficient increases in serum 25(OH)D levels, but did not improve lower-extremity power, strength, or lean mass.
Commentary
Vitamin D deficiency is common in older adults (prevalence of about 41% in US adults ≥ 65 years old, according to Forrest et al2) and is likely due to dietary deficiency, reduced sun exposure (lifestyle), and decreased intestinal calcium absorption. As such, vitamin D deficiency has historically been a topic of debate and of interest in geriatric medicine, as it relates to muscle weakness, which in turn leads to increased susceptibility to falls.3 Interestingly, vitamin D receptors are expressed in human skeletal muscle,4 and in one study, 3-month supplementation of vitamin D led to an increase in type II skeletal muscle fibers in older women.5 Similarly, results from a meta-analysis of 5 randomized controlled trials (RCTs)6 showed that vitamin D supplementation may reduce fall risk in older adults by 22% (corrected odds ratio, 0.78; 95% confidence interval, 0.64-0.92). Thus, in keeping with this general theme of vitamin D supplementation yielding beneficial effects in clinical outcomes, clinicians have long accepted and practiced routine vitamin D supplementation in caring for older adults.
In more recent years, the role of vitamin D supplementation in primary care has become controversial,7 as observed in a recent paradigm shift of moving away from routine supplementation for fall and fracture prevention in clinical practice.8 In a recent meta-analysis of 33 RCTs in older community-dwelling adults, supplementation with vitamin D with or without calcium did not result in a reduction of hip fracture or total number of fractures.9 Moreover, the United States Preventive Services Task Force (USPSTF) recently published updated recommendations on the use of vitamin D supplementation for primary prevention of fractures10 and prevention of falls11 in community-dwelling adults. In these updated recommendations, the USPSTF indicated that insufficient evidence exists to re
Vitamin D supplementation is no longer routinely recommended for fall and fracture prevention. However, if we believe that poor lower extremity muscle strength is a risk factor for falls,12 then the question of whether vitamin D has a beneficial role in improving lower extremity strength in older adults needs to be addressed. Results regarding the effect of vitamin D supplementation on muscle function have so far been mixed. For example, in a randomized, double-blinded, placebo-controlled trial of 160 postmenopausal women with low vitamin D level (< 20 ng/mL), vitamin D3 supplementation at 1000 IU/day for 9 months showed a significant increase in lower extremity muscle strength.13 However, in another randomized double-blinded, placebo-controlled trial of 130 men aged 65 to 90 years with low vitamin D level (< 30 ng/mL) and an SPPB score of ≤ 9 (mild-moderate limitation in mobility), daily supplementation with 4000 IU of vitamin D3 for 9 months did not result in improved SPPB score or gait speed.14 In the study reported by Shea et al, the authors showed that 800 IU of daily vitamin D supplementation (consistent with the Institute of Medicine [IOM] recommendations for older adults15) in community-dwelling older adults with vitamin D deficiency (< 20 ng/mL) did not improve lower extremity muscle strength. This finding is significant in that it adds further evidence to support the rationale against using vitamin D supplementation for the sole purpose of improving lower extremity muscle function in older adults with vitamin D deficiency.
Valuable strengths of this study include its randomized, double-blinded, placebo-controlled trial design testing the IOM recommended dose of daily vitamin D supplementation for older adults. In addition, compared to some of the prior studies mentioned above, the study population included both males and females, although the final study population resulted in some gender bias (with male predominance). Moreover, participants were followed for a sufficient amount of time (1 year), with an excellent adherence rate (only 3 were lost to follow-up) and with corresponding improvement in vitamin D levels. Finally, the use of SPPB as a readout for primary outcome should also be commended, as this assessment is a well-validated method for measuring lower extremity function with scaled scores that predict poor outcomes.16 However, some limitations include the aforementioned predominance of male participants and Caucasian race in both intervention and control groups, as well as discrepancies between the measurement methods for serum vitamin D levels (ie, finger-stick cards versus clinical lab measurement) that may have underestimated the actual serum 25(OH)D levels.
Applications for Clinical Practice
While the null findings from the Shea and colleagues study are applicable to healthier community-dwelling older adults, they may not be generalizable to the care of more frail older patients due to their increased risks for falls and high vulnerability to adverse outcomes. Thus, further studies that account for baseline sarcopenia, frailty, and other fall-risk factors (eg, polypharmacy) are needed to better evaluate the value of vitamin D supplementation in this most vulnerable population.
— Caroline Park, MD, PhD, and Fred Ko, MD
Icahn School of Medicine at Mount Sinai, New York, NY
Study Overview
Objective. To test the effect of 12 months of vitamin D supplementation on lower-extremity power and function in older community-dwelling adults screened for low serum 25-hydroxyvitamin D (25(OH)D).
Design. A single-center, double-blind, randomized placebo-controlled study in which participants were assigned to 800 IU of vitamin D3 supplementation or placebo daily and were followed over a total period of 12 months.
Setting and participants. A total of 100 community-dwelling men and women aged ≥ 60 years with serum 25(OH)D ≤ 20 ng/mL at screening participated. Participants were prescreened by phone, and were excluded if they met any of the following exclusion criteria: vitamin D supplement use > 600 IU/day (for age 60-70 years) or > 800 IU/day (for age ≥ 71 years); vitamin D injection within the previous 3 months; > 2 falls or 1 fall with injury in past year; use of cane, walker, or other indoor walking aid; history of kidney stones within past 3 years; hypercalcemia (serum calcium > 10.8 mg/dL); renal dysfunction (glomerular filtration rate, < 30 mL/min); history of liver disease, sarcoidosis, lymphoma, dysphagia, or other gastrointestinal disorder; neuromuscular disorder affecting lower-extremity function; hip replacement within the past year; cancer treatment in the past 3 years; treatment with thiazide diuretics > 37.5 mg, teriparatide, denosumab, or bisphosphonates within the past 2 years; oral steroids (for > 3 weeks in the past 6 months); and use of fat malabsorption products or anticonvulsive therapy.
Main outcome measures. The primary outcome was leg extensor power assessed using a computer-interfaced bilateral Keiser pneumatic leg press. Secondary outcomes to measure physical function included: (1) backward tandem walk test (which is an indicator of balance and postural control during movement1); (2) Short Physical Performance Battery (SPPB) testing, which includes a balance assessment (ability to stand with feet positioned normally, semi-tandem, and tandem for 10s), a timed 4-m walk, and a chair stand test (time to complete 5 repeated chair stands); (3) stair climbing (ie, time to climb 10 steps, as a measure of knee extensor strength and functional capacity); and (4) handgrip strength (using a dynamometer). Lean tissue mass was assessed by dual X-ray absorptiometry (DEXA scan). Finally, other measures included serum total 25(OH)D levels measured at baseline, 4, 8, and 12 months, as well as 24-hour urine collection for urea-nitrogen and creatinine measurements.
Main results. Of the 2289 individuals screened for the study, 100 met eligibility criteria and underwent randomization to receive either 800 IU vitamin D supplementation daily (n = 49) or placebo (n = 51). Three patients (2 in vitamin D group and 1 in placebo group) were lost to follow up. The mean age of all participants was 69.6 ± 6.9 years. In the vitamin D group versus the control group, respectively, the percent male: female ratio was 66:34 versus 63:37, and percent Caucasian was 75% versus 82%. Mean body mass index was 28.2 ± 7.0 and mean serum 25(OH)D was 20.2 ± 6.7 ng/mL. At the end of the study (12 months), 70% of participants given vitamin D supplementation had 25(OH)D levels ≥ 30 ng/mL and all participants had levels ≥ 20 ng/mL. In the placebo group, the serum 25(OH)D level was ≥ 20 ng/mL in 54% and ≥ 30 ng/mL in 6%. The mean serum 25(OH)D level increased to 32.5 ± 5.1 ng/mL in the vitamin D–supplemented group, but no significant change was found in the placebo group (treatment × time, P < 0.001). Overall, the serum 1,25 (OH)2D3 levels did not differ between the 2 groups over the intervention period (time, P = 0.49; treatment × time, P = 0.27). Dietary intake of vitamin D, calcium, nitrogen, and protein did not differ or change over time between the 2 groups. The change in leg press power, function, and strength did not differ between the groups over 12 months (all treatment × time, P values ≥ 0.60). A total of 27 falls were reported (14 in vitamin D versus 9 in control group), of which 9 were associated with injuries. There was no significant change in lean body mass at the end of the study period in either group (treatment × time, P = 0.98).
Conclusion. In community-dwelling older adults with vitamin D deficiency (≤ 20 ng/mL), 12-month daily supplementation with 800 IU of vitamin D3 resulted in sufficient increases in serum 25(OH)D levels, but did not improve lower-extremity power, strength, or lean mass.
Commentary
Vitamin D deficiency is common in older adults (prevalence of about 41% in US adults ≥ 65 years old, according to Forrest et al2) and is likely due to dietary deficiency, reduced sun exposure (lifestyle), and decreased intestinal calcium absorption. As such, vitamin D deficiency has historically been a topic of debate and of interest in geriatric medicine, as it relates to muscle weakness, which in turn leads to increased susceptibility to falls.3 Interestingly, vitamin D receptors are expressed in human skeletal muscle,4 and in one study, 3-month supplementation of vitamin D led to an increase in type II skeletal muscle fibers in older women.5 Similarly, results from a meta-analysis of 5 randomized controlled trials (RCTs)6 showed that vitamin D supplementation may reduce fall risk in older adults by 22% (corrected odds ratio, 0.78; 95% confidence interval, 0.64-0.92). Thus, in keeping with this general theme of vitamin D supplementation yielding beneficial effects in clinical outcomes, clinicians have long accepted and practiced routine vitamin D supplementation in caring for older adults.
In more recent years, the role of vitamin D supplementation in primary care has become controversial,7 as observed in a recent paradigm shift of moving away from routine supplementation for fall and fracture prevention in clinical practice.8 In a recent meta-analysis of 33 RCTs in older community-dwelling adults, supplementation with vitamin D with or without calcium did not result in a reduction of hip fracture or total number of fractures.9 Moreover, the United States Preventive Services Task Force (USPSTF) recently published updated recommendations on the use of vitamin D supplementation for primary prevention of fractures10 and prevention of falls11 in community-dwelling adults. In these updated recommendations, the USPSTF indicated that insufficient evidence exists to re
Vitamin D supplementation is no longer routinely recommended for fall and fracture prevention. However, if we believe that poor lower extremity muscle strength is a risk factor for falls,12 then the question of whether vitamin D has a beneficial role in improving lower extremity strength in older adults needs to be addressed. Results regarding the effect of vitamin D supplementation on muscle function have so far been mixed. For example, in a randomized, double-blinded, placebo-controlled trial of 160 postmenopausal women with low vitamin D level (< 20 ng/mL), vitamin D3 supplementation at 1000 IU/day for 9 months showed a significant increase in lower extremity muscle strength.13 However, in another randomized double-blinded, placebo-controlled trial of 130 men aged 65 to 90 years with low vitamin D level (< 30 ng/mL) and an SPPB score of ≤ 9 (mild-moderate limitation in mobility), daily supplementation with 4000 IU of vitamin D3 for 9 months did not result in improved SPPB score or gait speed.14 In the study reported by Shea et al, the authors showed that 800 IU of daily vitamin D supplementation (consistent with the Institute of Medicine [IOM] recommendations for older adults15) in community-dwelling older adults with vitamin D deficiency (< 20 ng/mL) did not improve lower extremity muscle strength. This finding is significant in that it adds further evidence to support the rationale against using vitamin D supplementation for the sole purpose of improving lower extremity muscle function in older adults with vitamin D deficiency.
Valuable strengths of this study include its randomized, double-blinded, placebo-controlled trial design testing the IOM recommended dose of daily vitamin D supplementation for older adults. In addition, compared to some of the prior studies mentioned above, the study population included both males and females, although the final study population resulted in some gender bias (with male predominance). Moreover, participants were followed for a sufficient amount of time (1 year), with an excellent adherence rate (only 3 were lost to follow-up) and with corresponding improvement in vitamin D levels. Finally, the use of SPPB as a readout for primary outcome should also be commended, as this assessment is a well-validated method for measuring lower extremity function with scaled scores that predict poor outcomes.16 However, some limitations include the aforementioned predominance of male participants and Caucasian race in both intervention and control groups, as well as discrepancies between the measurement methods for serum vitamin D levels (ie, finger-stick cards versus clinical lab measurement) that may have underestimated the actual serum 25(OH)D levels.
Applications for Clinical Practice
While the null findings from the Shea and colleagues study are applicable to healthier community-dwelling older adults, they may not be generalizable to the care of more frail older patients due to their increased risks for falls and high vulnerability to adverse outcomes. Thus, further studies that account for baseline sarcopenia, frailty, and other fall-risk factors (eg, polypharmacy) are needed to better evaluate the value of vitamin D supplementation in this most vulnerable population.
— Caroline Park, MD, PhD, and Fred Ko, MD
Icahn School of Medicine at Mount Sinai, New York, NY
1. Husu P, Suni J, Pasanen M, Miilunpalo S. Health-related fitness tests as predictors of difficulties in long-distance walking among high-functioning older adults. Aging Clin Exp Res. 2007;19:444-450.
2. Forrest KYZ, Stuhldreher WL. Prevalence and correlates of vitamin D deficiency in US adults. Nutr Res. 2011;31:48-54.
3. Bischoff-Ferrari HA, Giovannucci E, Willett WC, et al. Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes. Am J Clin Nutr. 2006;84:1253.
4. Simpson RU, Thomas GA, Arnold AJ. Identification of 1,25-dihydroxyvitamin-D3 receptors and activities in muscle. J Biol Chem. 1985;260:8882-8891.
5. Sorensen OH, Lund BI, Saltin B, et al. Myopathy in bone loss ofaging - improvement by treatment with 1alpha-hydroxycholecalciferol and calcium. Clinical Science. 1979;56:157-161.
6. Bischoff-Ferrari HA, Dawson-Hughes B, Willett WC, et al. Effect of vitamin D on falls - A meta-analysis. JAMA. 2004;291:1999-2006.
7. Lewis JR SM, Daly RM. The vitamin D and calcium controversy: an update. Curr Opin Rheumatol. 2019;31:91-97.
8. Schwenk T. No value for routine vitamin D supplementation. NEJM Journal Watch. December 26, 2018.
9. Zhao JG, Zeng XT, Wang J, Liu L. Association between calcium or vitamin D supplementation and fracture incidence in community-dwelling older adults: a systematic review and meta-analysis. JAMA. 2017;318:2466-2482.
10. Grossman DC, Curry SJ, Owens DK, et al. Vitamin D, calcium, or combined supplementation for the primary prevention of fractures in community-dwelling adults US Preventive Services Task Force Recommendation Statement. JAMA. 2018;319:1592-1599.
11. Grossman DC, Curry SJ, Owens DK, et al. Interventions to prevent falls in community-dwelling older adults US Preventive Services Task Force Recommendation Statement. JAMA. 2018;319:1696-1704.
12. Tinetti ME, Speechley M, Ginter SF. Risk-factors for falls among elderly persons living in the community. N Engl J Med. 1988;319:1701-1707.
13. Cangussu LM, Nahas-Neto J, Orsatti CL, et al. Effect of vitamin D supplementation alone on muscle function in postmenopausal women: a randomized, double-blind, placebo-controlled clinical trial. Osteoporos Int. 2015;26:2413-2421.
14. Levis S, Gomez-Marin O. Vitamin D and physical function in sedentary older men. J Am Geriatr Soc. 2017;65:323-331.
15. Ross CA TC, Yaktine AL, Del Valle HB. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium. National Academies Press. 2011.
16. Guralnik JM, Ferrucci L, Simonsick EM, et al. Lower-extremity function in persons over the age of 70 years as a predictor of subsequent disability. N Engl J Med. 1995;332:556-561
1. Husu P, Suni J, Pasanen M, Miilunpalo S. Health-related fitness tests as predictors of difficulties in long-distance walking among high-functioning older adults. Aging Clin Exp Res. 2007;19:444-450.
2. Forrest KYZ, Stuhldreher WL. Prevalence and correlates of vitamin D deficiency in US adults. Nutr Res. 2011;31:48-54.
3. Bischoff-Ferrari HA, Giovannucci E, Willett WC, et al. Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes. Am J Clin Nutr. 2006;84:1253.
4. Simpson RU, Thomas GA, Arnold AJ. Identification of 1,25-dihydroxyvitamin-D3 receptors and activities in muscle. J Biol Chem. 1985;260:8882-8891.
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