The effects of single high-dose or daily low-dosage oral colecalciferol treatment on vitamin D levels and muscle strength in postmenopausal women

INTRODUCTION

Vitamin D deficiency is a common health problem. Vitamin D supplements are used to improve vitamin D status; however, there are contradictory data related to what doses to give and how often they should be given. Many studies have investigated the effects of vitamin D supplementation on muscle strength, but the results remain controversial. We aimed to compare the effects and safety of single high-dose with daily low-dose oral colecalciferol on 25(OH)D levels and muscle strength in postmenopausal women with vitamin D deficiency or insufficiency.

METHODS AND DESIGN

Sixty healthy postmenopausal women who had serum vitamin D levels < 20 ng/mL (50 nmol/L) were enrolled in the study. Group 1 (n = 32) was given daily oral dosages of 800 IU vitamin D3, and group 2 (n = 28) was given a single oral dose of 300,000 IU vitamin D3. Serum vitamin D levels and muscle strengths were measured at the beginning, 4th, and 12th week. Muscle strength tests were performed at 60° using a Biodex system 3 isokinetic dynamometer.

RESULTS

Pretreatment vitamin D levels did not differ between the two groups (10.2 ± 4.4 ng/mL (25,4 ± 10,9 nmol/L); 9.7 ± 4.4 ng/mL (24,2 ± 10,9 nmol/L), p > 0.05). A significant increase in vitamin D levels was observed in both groups at 4 and 12 weeks after vitamin D3 treatment. The increase in the single-dose group was significantly higher than the daily low-dosage group at the 4th week (35.9 ± 9.6 ng/mL (89,6 ± 23,9 nmol/L), 16.9 ± 5.8 ng/mL (42,1 ± 14,4 nmol/L), p = 0.01). The increase in the single-dose group was significantly higher than in the daily low dosage group at the 12th week (23.4 ± 4.7 ng/mL (58,4 ± 11,7 nmol/L), 19.8 ± 7.2 ng/mL (49,4 ± 17,9 nmol/L), p = 0.049). The quadriceps muscle strength score increased significantly in the daily group at the 4th week (p = 0.038). The hamstring muscle strength score increased significantly in the daily group at the 12th week (p = 0.037).

CONCLUSION

Although daily administration routes are more effective in improving muscle strength, a single administration is more effective in increasing vitamin D levels.

TRIAL REGISTRATION NUMBER

ISRCTN14226530 (04.07.2018), Name of the registry: ISRCTN registry, The study was retrospectively registered.

Nocturnal hypoxia and functional outcome in stroke patients

BACKGROUND

Sleep disorders and nocturnal hypoxia are common in patients with cerebrovascular disease. Sleep-disordered breathing is associated with a poor functional outcome in stroke patients.

OBJECTIVE

We investigated the relationship between nocturnal hypoxia and functional outcome in the rehabilitation phase of stroke patients.

METHODS

Thirty patients with stroke and 20 controls were included. Functional status was evaluated with the Functional Independence Measure (FIM). Pulse oximetry was performed overnight from 21.00  h to 07.00  h. Baseline awake oxygen saturation, nocturnal oxygen saturation, the lowest nocturnal oxygen saturation, and the >4% Oxygen Desaturation Index (ODI) were calculated.

RESULTS

The mean oxygen saturation measurements were not significantly different among the groups (p >  0.05). There was no significant relationship between the FIM scores and the oxygen saturation measurements of the stroke patients (p >  0.05). The baseline oxygen saturation in patients with disease duration of 3 months or less was 94.67, and it was 96.56 (p = 0.016) in those with disease duration of more than 3 months.

CONCLUSION

This study showed that nocturnal oxygen saturation was not associated with functional outcome in therehabilitation phase of stroke patients.