Vitamin D status among the elderly Chinese population: a cross-sectional analysis of the 2010–2013 China national nutrition and health survey (CNNHS)

Abstract

BackgroundVitamin D inadequacy is common among the elderly, especially within the Asian population. The vitamin D status among healthy adults in the elderly Chinese population was evaluated.MethodsA total of 6014 healthy adults aged 60 years or older (2948 men, 3066 women) participated in this descriptive cross-sectional analysis. Possible predictors of vitamin D inadequacy were evaluated via multiple logistic regression analyses.ResultsThe median serum 25-hydroxyvitamin D (25(OH)D) levels were 61.0 nmol/l (interquartile range (IQR) 44.3–80.6, range 5.1–154.5) for men and 53.7 nmol/l (IQR 38.8–71.0, range 6.0–190.0) for women, with 34.1% (95% confidence interval (CI) 32.4–35.8) of men and 44.0% (95% CI 42.2–45.8) of women presenting vitamin D inadequacy (25(OH)D <50 nmol/l). According to the multivariate logistic regression analyses, vitamin D inadequacy was positively correlated with female gender (P <0.0001), underweight (P = 0.0259), the spring season (P <0.0001), low ambient UVB levels (P <0.0001) and living in large cities (P = 0.0026). For men, vitamin D inadequacy was positively correlated with the spring season (P = 0.0015), low ambient UVB levels (P <0.0001) and living in large cities (P = 0.0022); for women, vitamin D inadequacy was positively correlated with the spring season (P = 0.0005) and low ambient UVB levels (P <.0001).ConclusionsVitamin D inadequacy is prevalent among the elderly population in China. Because residing in regions with low ambient UVB levels increases the risk of vitamin D inadequacy both for men and women, vitamin D supplementation and sensible sun exposure should be encouraged, especially during the cooler seasons. Further studies are required to determine the optimal vitamin D intake and sun exposure levels to maintain sufficient vitamin D levels in the elderly Chinese population.

Vitamin D status in an Australian patient population: a large retrospective case series focusing on factors associated with variations in serum 25(OH)D

“…Contrary to previous studies,31–33 we found that 25(OH)D level increased with increasing age. Vitamin D supplementation could have also contributed to this finding.…”

“…Serum 25(OH)D levels were shown to increase with increasing age, but older patients were found to be more likely to be prescribed with vitamin D supplementation (table 4), likely resulting in higher serum 25(OH)D measured. This could explain the contradiction of our findings to data demonstrating higher prevalence of vitamin D deficiency with increasing age in both men and women,31–33 which did not take into account supplementation. Contrary to previous studies that demonstrated the association of vitamin D deficiency and neurological disorders such as Parkinson’s disease, Alzheimer’s disease, MS and epilepsy,34–38 our data showed that patients admitted to the neurology specialty had the highest mean 25(OH)D level compared with patients from all other specialties.…”

Vitamin D Status of Residents in Taiyuan, China and Influencing Factors

“…The current study found that 40.9% of women and 20.5% of men were vitamin D deficient in Taiyuan during winter. Prevalence was higher than reported recently in China in a nationally representative sample of adults over 60 years, in which 12.0% of women and 7.8% of men were classified as deficient over all seasons [ 27 ]. However, prevalence in the current study was lower than peak vitamin D deficiency which occurred in spring, where 50% of women and 40% of men were deficient [ 27 ].…”

The Relationship Between Serum 25-Hydroxyvitamin D Levels and Physical Performance in Community-Dwelling Older Adults

“…In the present study, 36.51% of males and 50.72% of females had vitamin D levels below 20 ng/mL; however, a recent study of Chinese individuals aged 60 years or older also reported that 34.1% of males and 44.0% of females had inadequate vitamin D levels (<20 ng/mL). 34) Furthermore, countries with low latitudes, such as Australia, Indonesia, and Brazil, also have a lower prevalence of vitamin D deficiency. 13) These differences might be due to the differences in age, ethnicity, lifestyle, diets fortified with vitamin D, or geographical difference leading to differences in sun exposure.…”