The Association between Vitamin D Deficiency and Changes in Cognitive Functions in Chinese Older Adults: A Prospective Cohort Study.
Current Alzheimer research
BACKGROUND:Along with the problem of population aging, the prevalence of dementia is gradually increasing. Associations between vitamin D deficiency (VDD) and cognitive functions remain unclear. OBJECTIVES:We aimed to determine the relationship between VDD and changes in cognitive performance in community-dwelling older adults. METHODS:In this longitudinal cohort study, participants aged ≥65 years were enrolled in March, 2016. The serum level of 25-hydroxy-vitamin D was analyzed by liquid-chromatography-tandem-- mass-spectrometry at baseline. VDD was defined as less than 20 ng/mL. All participants completed a health status questionnaire. Cognitive functions were evaluated by the Wechsler Adult Intelligence Scale-Revised in China at baseline and each visit. The linear mixed-effects model was utilized to examine the association between baseline VDD and changes in cognitive functions. RESULTS:In total, 866 participants were included in our study, with a mean duration of 3 years. VDD was markedly associated with lower full intelligence quotient (FIQ) (β: -3.355, 95% confidence interval [CI]:-4.165,-2.545), verbal intelligence quotient (VIQ) (β: -3.420, 95%CI: -4.193,-2.647), performance intelligence quotient (PIQ) (β: -2.610, 95%CI: -3.683,-1.537), comprehension (β: -0.630, 95%CI: -1.022,-0.238), information (β: -0.354, 95%CI: -0.699,-0.008), arithmetic (β: -1.065, 95%CI: -1.228,-0.902), digit span (β: -0.370, 95%CI: -0.547,-0.192), vocabulary (β: -0.789, 95%CI: -1.084,-0.493), picture completion (β: -0.391, 95%CI: -0.761,-0.022), block design (β: -0.412, 95%CI: -0.697,-0.127), picture arrangement (β: -0.542, 95%CI: -0.909,-0.174), and object assembly (β: -0.492, 95%CI: -0.818,-0.165) than those with adequacy. CONCLUSION:A higher frequency of VDD was associated with lower scores of FIQ, VIQ, PIQ and subtests on memory and executive function. Future randomized controlled trials are warranted to further verify the conclusions.
10.2174/0115672050266769231025060359
Making the sunshine vitamin - How much sun exposure is needed to maintain 25-hydroxy vitamin D concentration?
Photochemistry and photobiology
Our objective was to calculate the time in the sun necessary to maintain existing 25-hydroxyvitamin D (25(OH)D) concentration at locations across Australia and New Zealand. We used a microsimulation model to estimate changes in monthly 25(OH)D concentration using data on standard erythemal dose, solar zenith angle, and climatological ozone. We estimated the number of standard vitamin D doses per 10-min interval and used a dose-response equation to determine the average time in the sun to maintain existing 25(OH)D concentration according to month and time of day. Across all locations in summer, 5-10 min outdoors between 8 a.m. and 4 p.m. on most days of the week, with 35% of the body surface area exposed, is sufficient to maintain existing 25(OH)D concentration. In winter, at mid-to-high latitudes, time outdoors during the middle of the day is required. In winter, with 10% of the body surface area exposed, greater than 45 min in the middle of the day is required in most locations to maintain existing 25(OH)D concentration. These data can be used to inform guidelines regarding maintaining vitamin D via sun exposure and may help health practitioners identify patients who may be vitamin D deficient.
10.1111/php.13854
25-Hydroxy vitamin D level is associated with sleep disturbances in patients with chronic kidney disease on hemodialysis: a cross-sectional study
Yavuz Demet,Demirağ Mehmet Derya,Yavuz Rahman,Karagöz Özen Düriye Sila,Ramazanoğlu Zeynep Banu
Turkish journal of medical sciences
Background/aim:Deficient levels of vitamin D are an important factor in the pathogenesis of some neurodegenerative diseases. The aim of this study is to determine the relationship between vitamin D deficiency and depression status and sleep disorders of patients on dialysis. Materials and methods:In this cross-sectional study, 121 hemodialysis patients were enrolled. All patients had been on hemodialysis for at least six months at the time of the study. Sleep quality and depression status were measured by using specific inventories. All the patients filled out Pittsburg Sleep Quality Index (PSQI) and Beck Depression Inventory (BDI), and gave blood samples. Vitamin D levels were measured for 121 patients, and statistical analysis was done by using SPSS. Results:Regression analyses demonstrated that low levels of 25(OH)D and high BDI score were independent risk factors for poor sleep quality [ORs were 0.668 (0.566–0.789), 1.080 (1.001–1.164), and 1.080 (1.001–1.164), respectively]. Conclusion:Our results suggest that deficiency of 25(OH)D is an important independent risk factor for poor sleep quality in hemodialysis patients.
10.3906/sag-1908-87
Lifestyle and 25-hydroxy-vitamin D among community-dwelling old adults with dementia, mild cognitive impairment, or normal cognitive function.
Aging clinical and experimental research
BACKGROUND:Several studies have indicated that older adults with cognitive impairment have a poorer lifestyle than their healthy peers including lower 25-hydroxy-vitamin D levels (25OHD). AIM:To investigate the associations between lifestyle and 25OHD depending on cognitive status among old adults. METHODS:Community-dwelling old adults (65-96 years) participated in this cross-sectional study based on the Age-Gene/Environment-Susceptibility-Reykjavik-Study. The analytical sample included 5162 subjects who were stratified by cognitive status, i.e., dementia (n = 307), mild cognitive impairment (MCI, n = 492), and normal cognitive status (NCS, n = 4363). Lifestyle variables were assessed and 25OHD was measured. The associations between lifestyle and 25OHD were calculated using linear models correcting for potential confounders. RESULTS:According to linear regression models, 25OHD was significantly lower in older people with dementia (53.8 ± 19.6 nmol/L) than in NCS participants (57.6 ± 17.7 nmol/L). Cod liver oil (7.1-9.2 nmol/L, P < 0.001) and dietary supplements (4.4-11.5 nmol/L, P < 0.001) were associated with higher 25OHD in all three groups. However, physical activity ≥ 3 h/week (2.82 nmol/L, P < 0.001), BMI < 30 kg/m (5.2 nmol/L, P < 0.001), non-smoking (4.8 nmol/L, P < 0.001), alcohol consumption (2.7 nmol/L, P < 0.001), and fatty fish consumption ≥ 3x/week (2.6 nmol/L, P < 0.001) were related to higher 25OHD in NCS only, but not in participants with dementia or MCI. DISCUSSION:Older people living in Iceland with dementia are at higher risk for 25OHD deficiency when compared to healthy individuals. Physical activity reported among participants with dementia, and MCI is low and is not significantly associated with 25OHD. CONCLUSIONS:Lifestyle factors among NCS participants are associated with 25OHD levels. Importantly, healthy lifestyle should be promoted among individuals with MCI and dementia.
10.1007/s40520-020-01531-1
Association between lower serum vitamin D (25-hydroxy-cholecalciferol) concentrations and cognitive impairment in older adults: data from a populational-based cohort study in a middle-income country.
Public health nutrition
OBJECTIVE:To investigate the association between serum vitamin D (25-hydroxy-cholecalciferol) (25(OH)D) concentrations and cognitive impairment in older adults living in Southern Brazil. DESIGN:Cross-sectional analysis using data from the second follow-up wave of the populational-based EpiFloripa Aging Cohort Study was collected in 2013-2014. SETTING:Cognitive impairment was evaluated using the Mini-Mental State Examination (MMSE). Blood samples were collected to measure serum vitamin D concentrations using a chemiluminescent microparticle immunoassay. Vitamin D concentrations were distributed in quartiles (Q1: 4·0-20·7 ng/ml; Q2: 20·8-26·6 ng/ml; Q3: 26·7-32·0 ng/ml and Q4: 32·1-60·1 ng/ml), and its association with cognitive impairment was tested by crude and adjusted logistic regression (sociodemographic, behavioural and health aspects) using Q4 as a reference group. PARTICIPANTS:200 men and 371 women aged 60 years or older participated in this study. RESULTS:The prevalence of probable cognitive impairment was 21·7 %. Those without cognitive impairment had a higher mean of vitamin D serum concentrations (26·8 . 24·6, = 0·014). In the crude analysis, only individuals in Q2 of vitamin D presented an increased risk for probable cognitive impairment compared with Q4 (highest quartile) (OR 2·65, 95 % CI 1·46, 4·81), remaining significant in the adjusted analysis (OR 6·04, 95 % CI 2·78, 13·13). While Q1 (lowest quartile) was not associated in the crude analysis, but when adjusted, an increased risk of cognitive impairment was observed. CONCLUSION:The lowest quartile of vitamin D was directly associated with probable cognitive impairment in older adults in Southern Brazil. More studies are needed to investigate whether maintaining adequate serum levels may represent a significant factor in preventing age-related neurological disorders as well as to verify the need for new cutoff points for this age group.
10.1017/S1368980021004407
Serum 25-hydroxy vitamin D level is associated with cognitive impairment in people aged 65 years and older.
Lu Yan,Li Jie,Hu Tingjun,Huang Gaozhong
Annals of palliative medicine
BACKGROUND:Vitamin D deficiency is prevalent in the population, especially in older people. In recent years, studies have revealed an association between a low vitamin D level and cognitive decline. The present research aimed to investigate the relationship of serum 25-hydroxyvitamin D (25-OH-D) level with cognitive function in senior patients. METHODS:We recruited 299 patients aged 65 years and older. The patients were grouped based on their serum 25-OH-D levels into group A (<10.0 ng/mL), B (10.0-19.9 ng/mL), and C (≥20.0 ng/mL). Cognitive function was assessed with the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Clinical Dementia Rating (CDR) scale, and Activities of Daily Living (ADL) scale. RESULTS:MMSE and MoCA scores were significantly lower in group A (26.02±3.99 and 21.56±5.59, respectively) than in group B (27.34±2.79 and 23.94±4.74, respectively) and group C (27.65±2.54 and 24.95±4.45, respectively). The proportion of patients with cognitive impairment was increased in group A (71.1%) compared to group B (55.3%) and group C (43.9%), and the difference was statistically significant (both P<0.01). Spearman's correlation analysis showed that MMSE and MoCA had a positive relationship with serum 25-OH-D level (β=0.173 and 0.243, both P<0.01) with adjustments for factors as age, sex, and education level. Stepwise regression analysis indicated that MMSE and MoCA scores were correlated with serum 25-OH-D level, age, and education level. CONCLUSIONS:A lower level of 25-OH-D is common in senior patients and is associated with cognitive impairment. Patients with severe deficiency of vitamin D (serum 25-OH-D level <10 ng/mL) have lower MMSE and MoCA scores and a higher risk of cognitive dysfunction.
10.21037/apm-21-568
Association of serum 25-hydroxy vitamin D with gait speed and handgrip strength in patients on hemodialysis.
BMC nephrology
BACKGROUND:Muscle dysfunction is prevalent in dialysis patients. Gait speed and handgrip strength are simple and reliable methods of assessing muscle function. Numerous observational studies have linked 25-hydroxy vitamin D[25(OH)D] status with gait speed and handgrip strength in populations without kidney diseases. This study aimed to evaluate the potential associations of 25(OH)D status with gait speed and handgrip strength in patients on hemodialysis. METHODS:In this observational cross-sectional study, demographic data, biological data, and dialysis parameters were collected. Gait speed and handgrip strength were measured. Multiple linear regression and logistic regression analysis were used to investigate the relationship of 25(OH)D status with gait speed and handgrip strength after adjusting for potential confounders. RESULTS:Overall, a total of 118 participants undergoing hemodialysis were included. Seventy-one (60.2%) participants were male. The median 25(OH)D status in participants was 11.58 (interquartile range: 8.51 to 15.41) ng/ml. When controlling for age, gender, dialysis vintage, and other confounders with a p-value < 0.15 in univariate analyses, 25(OH)D was significantly positively associated with gait speed (β = 0.16, 95% CI 0.05 to 0.28, p = 0.006) and handgrip strength (β = 3.83, 95% CI 1.09 to 6.56, p = 0.007). CONCLUSION:Our study showed that 25(OH)D status seemed to be associated with gait speed and handgrip strength in patients on hemodialysis. However, these results were not robust. The relationships between 25(OH)D status and gait speed and handgrip should be further explored.
10.1186/s12882-022-02973-7