TITLE:
Vitamin D3 Supplementation Improved Physical Performance in Healthy Older Adults in Japan: A Pilot Study
AUTHORS:
Noboru Hasegawa, Miyako Mochizuki, Mayumi Kato, Nobuko Shimizu, Takako Yamada
KEYWORDS:
Serum 25-Hydroxyvitamin D, Cognitive Function, Physical Function, Aging, Sarcopenia
JOURNAL NAME:
Health,
Vol.10 No.9,
September
19,
2018
ABSTRACT: Japan has the highest proportion of older adults and so-called “Super-aged society” in the world. These results suggested that the prevalence of both cognitive and physical functional impairment increases with age. Therefore, the present study was designed to investigate the effect of vitamin D3 supplementation in cognitive and physical functional impairment in healthy older adults in Japan. We enrolled 7 Japanese male (age: 76.0 ± 8.7) and 5 female (age: 78.3 ± 9.3) in this study. The physical function of even a person getting on a wheelchair could be tested in all subjects. Treatment group (n = 7) consisted of a 500 IU/day vitamin D3 corresponding to twice of daily requirement for 6 months. Blood was collected by venipuncture and the serum 25-hydroxy vitamin D (25 OHD), 1,25-hydroxy vitamin D (1,25 OHD), Ca and PTH concentration were measured. The Mini-Mental State Examination and the Montreal Cognitive Assessment-Japanese version were used for the cognitive function test. Physical function was measured objectively using the Timed Up and Go (TUG), 4-mgait speed test (4 MGS), 5-repetition sit-to-stand (5 STS), 30-second chair stand test (CS-30) and measurement of upper grip strength. Our results show that a 6-month intake of vitamin D3 increased serum 25 OHD within the insufficiency and sufficiency levels without changing 1,25 OHD, Ca and PTH concentration. And it significantly decreased 4 MGS without changing TUG, 5 STS, CS-30, upper grip strength and cognitive function. Serum 25 OHD cut-off values for skeletal muscle index, grip strength and 4 MGS in diagnosis of sarcopenia are 18.6 - 23.4 ng/mL. These findings suggest that serum 25 OHD levels (23.4 ng/mL) might improve moving capacity, lower limb muscle strength, and physical balance functional impairment.