scholarly journals Determinants of serum 25-hydroxyvitamin D in Hong Kong

2015 ◽  
Vol 114 (1) ◽  
pp. 144-151 ◽  
Author(s):  
Cuiling Xu ◽  
Ranawaka A. P. M. Perera ◽  
Yap-Hang Chan ◽  
Vicky J. Fang ◽  
Sophia Ng ◽  
...  

Vitamin D plays an important role in skeletal health throughout life. Some studies have hypothesised that vitamin D may reduce the risk of other diseases. Our study aimed to estimate age-specific and sex-specific serum 25-hydroxyvitamin D (25(OH)D) status and to identify the determinants of serum 25(OH)D status in Hong Kong, a subtropical city in southern China. In 2009–2010, households in Hong Kong were followed up to identify acute respiratory illnesses, and sera from 2694 subjects were collected in three to four different study phases to permit measurement of 25(OH)D levels at different times of the year. A questionnaire survey on diet and lifestyle was conducted among children, with simultaneous serum collection in April and May 2010. The mean of serum 25(OH)D levels in age groups ranged from 39 to 63 nmol/l throughout the year with the mean values in all age groups in spring below 50 nmol/l. Children aged 6–17 years, and girls and women had significantly lower serum 25(OH)D levels than adults, and boys and men, respectively (allP< 0·001). We estimated that serum 25(OH)D levels in Hong Kong followed a lagged pattern relative to climatic season by 5 weeks with lowest observed levels in early spring (March). For children aged 6–17 years, reporting a suntan, having at least 1 servings of fish/week and having at least 1 serving of eggs/week were independently associated with higher serum 25(OH)D levels. Adequate sunlight exposure and increased intake of dietary vitamin D could improve vitamin D status, especially for children and females in the winter and spring.

1982 ◽  
Vol 204 (1) ◽  
pp. 185-189 ◽  
Author(s):  
R L Horst ◽  
J L Napoli ◽  
E T Littledike

Vitamin D-deficient pigs, rats and chicks were repleted with four daily oral doses of crystalline ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) containing equal concentrations of each. At 24 h after the last dose, the plasma of each species was analysed for vitamin D and 25-hydroxyvitamin D by standard methods. The mean (+/- S.D.) ratios of plasma cholecalciferol to ergocalciferol concentration were 1.5 +/- 0.1 (pig). 1.7 +/- 0.1 (rat) and 6.3 +/- 1.2 (chick). The mean ratios of plasma 25-hydroxycholecalciferol to 25-hydroxyergocalciferol concentration were 4.0 +/- 0.1 (pig), 0.4 +/- 0.02 (rat) and 10.7 +/- 3.4 (chick). The mean plasma cholecalciferol/ergocalciferol ratios for the 24,25-dihydroxy-, 25,26-dihydroxy- and 1,25-dihydroxy-derivatives in the pig were 2.6 +/- 0.6, 5.8 +/- 1.3 and 5.8 +/- 0.8 respectively. This is the first evidence that mammals other than the New World monkey, like birds, discriminate between ergocalciferol and cholecalciferol. These data, therefore, suggest that species discrimination between the different forms of vitamin D is probably a general phenomenon in mammals. Moreover, this is the first indication of a species (rat) that discriminates against a cholecalciferol metabolite in favour of an ergocalciferol metabolite. Species discrimination against particular forms of vitamin D may be important to the choice of experimental animal models for studying the regulation of vitamin D metabolism and may also be an important consideration in dietary vitamin supplementation.


2021 ◽  
pp. 1-7
Author(s):  
Naomi Vather-Wu ◽  
Matthew D. Krasowski ◽  
Katherine D. Mathews ◽  
Amal Shibli-Rahhal

Background: Expert guidelines recommend annual monitoring of 25-hydroxyvitamin D (25-OHD) and maintaining 25-OHD ≥30 ng/ml in patients with dystrophinopathies. Objective: We hypothesized that 25-OHD remains stable and requires less frequent monitoring in patients taking stable maintenance doses of vitamin D. Methods: We performed a retrospective cohort study, using the electronic health record to identify 26 patients with dystrophinopathies with a baseline 25-OHD ≥30 ng/mL and at least one additional 25-OHD measurement. These patients had received a stable dose of vitamin D for ≥3 months prior to their baseline 25-OHD measurement and throughout follow-up. The main outcome measured was the mean duration time the subjects spent with a 25-OHD ≥30 ng/mL. Results: Only 19% of patients dropped their 25-OHD to <  30 ng/ml, with a mean time to drop of 33 months and a median nadir 25-OHD of 28 ng/mL. Conclusions: These results suggest that measurement of 25-OHD every 2–2.5 years may be sufficient in patients with a baseline 25-OHD ≥30 ng/mL and who are on a stable maintenance dose of vitamin D. Other patients may require more frequent assessments.


2017 ◽  
Vol 26 (1) ◽  
pp. 56-59
Author(s):  
Ivana Goluza ◽  
Jay Borchard ◽  
Nalin Wijesinghe ◽  
Kishan Wijesinghe ◽  
Nagesh Pai

Objectives: The objective of the current study was to examine the pathology test utilisation of 25-hydroxyvitamin D (25(OH)D) within an Australian inpatient psychiatric setting. Method: A retrospective audit of 300 random hospital files of those admitted as inpatients between Nov 2014 and Nov 2015 was undertaken. Data was quantitatively analysed and described. Results: The number of inpatients who had a vitamin D determination during their admission was 37/300 (12.33%). The mean vitamin D level of those tested was 51.63 nmol/l. Of those that were tested, 18/37 (48.6%) were mildly to moderately deficient. There was a statistically significant difference in age and length of stay between those that were and were not tested for vitamin D levels, p-value <0.001 and 0.017, respectively. In addition, a simple linear regression indicated a weak association between length of stay and vitamin D levels. Conclusion: This audit highlights vitamin D screening inadequacy. More research is recommended to establish tangible benefits of supplementation, while local practice provides valuable data for education and policy purposes.


2015 ◽  
Vol 114 (11) ◽  
pp. 1838-1844 ◽  
Author(s):  
Min Jung Ko ◽  
Sungha Yun ◽  
Kyungwon Oh ◽  
Kirang Kim

AbstractThe objective of this study was to examine whether high serum 25-hydroxyvitamin D (25(OH)D) concentration was associated with high skeletal muscle mass, taking into account the effects of sex and age among the participants of the Korea National Health and Nutrition Examination Survey (KNHANES) aged 40 years or older. This was a cross-sectional study using data from the 2009 to 2010 KNHANES; a total of 8406 subjects (3671 men and 4735 women) were included. The appendicular skeletal muscle mass index (ASMMI, kg/m2) was estimated to measure the skeletal muscle mass. Hypovitaminosis was classified when the level of serum 25(OH)D was <20 ng/ml. The general linear model adjusted for confounding factors was used to determine differences in means of ASMMI by 25(OH)D status. The mean values of ASMMI were higher for men when compared with women. Women had a greater proportion of hypovitaminosis (71·1 %) compared with men (53·2 %). After adjusting for multiple factors, men were seen to have significant differences in ASMMI based on 25(OH)D status regardless of age, showing a lower mean value of ASSMI in those with hypovitaminosis. However, there was no difference in ASMMI by 25(OH)D status among women in both younger and older age groups. In conclusion, we found that there might be a positive relationship between 25(OH)D and skeletal muscle mass in men, indicating that interventions to improve 25(OH)D levels that are aimed at increasing muscle mass could be beneficial for men with more rapid decreased rate of skeletal muscle mass.


2018 ◽  
Vol 39 (2) ◽  
pp. 260-265
Author(s):  
Yanhong Li ◽  
Yan Li ◽  
Xian Zhang ◽  
Lin Zhao ◽  
Liqin Chen ◽  
...  

Objectives: To determine the prevalence of vitamin D deficiency in 6- to 23-month-old children from 4 different ethnic groups, Han, Lisu, Hani, and Bai, in Yunnan Province of China. Methods: A large cohort of 938 young children aged 6 to 23 months who were living in Yunnan, China (23°28′-27°52′ N), were selected and recruited in this study. Venous-blood sampling was conducted in all the participants, and serum 25-hydroxyvitamin D [25(OH)D] levels were measured. The children’s physical status was measured. Results: General mean serum 25(OH)D level was 21.46 ± 7.95 ng/mL, which was obtained from a total of 938 cases. No significant difference was found in age, gender, height, and weight of participants from different ethnic groups. The mean 25(OH)D level was significantly lower in children of Lisu ethnic groups compared with that of Han and Hani participants, respectively ( P < .05). In addition, Bai children had lower 25(OH)D content than Hani children ( P < .001). Among the children with 25(OH)D sufficiency, the number of Lisu participants was significantly lower than Han children ( P < .001). Conclusion: The prevalence of vitamin D deficiency varied among the ethnically different children in Yunnan, China, and significantly fewer Lisu children maintained vitamin D sufficiency compared with other ethnic children. Recognizing these ethnic differences in treating children with vitamin D deficiency may improve the therapeutic outcome.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 743 ◽  
Author(s):  
Keiko Asakura ◽  
Norihito Etoh ◽  
Haruhiko Imamura ◽  
Takehiro Michikawa ◽  
Takahiro Nakamura ◽  
...  

Vitamin D insufficiency/deficiency is prevalent worldwide. We investigated the effect of vitamin D intake and ultraviolet ray (UV) exposure on serum vitamin D concentration in Japan. A total of 107 healthy adult participants were recruited from Hokkaido (43° N) and Kumamoto (33° N) prefectures. All participants undertook surveys in both summer and winter. Serum 25-hydroxyvitamin D (25(OH)D3) was examined, and vitamin D intake was assessed with a diet history questionnaire. UV exposure was measured with a wearable UV dosimeter. Regression analysis was performed to investigate the relationship between these factors, with covariates such as sun avoidance behavior. The prevalence of vitamin D insufficiency (serum 25(OH)D3; 12 ng/mL (30 nmol/L) ≤ and <20 ng/mL (50 nmol/L))/deficiency (<12 ng/mL) was 47.7% in summer and 82.2% in winter. UV exposure time was short in Kumamoto (the urban area), at 11.6 min in summer and 14.9 min in winter. In Hokkaido (the rural area), UV exposure time was 58.3 min in summer and 22.5 min in winter. Vitamin D intake was significantly associated with serum 25(OH)D3, and a 1 μg/1000kcal increase in intake was necessary to increase 25(OH)D3 by 0.88 ng/mL in summer and by 1.7 ng/mL in winter. UV exposure time was significantly associated with serum 25(OH)D3 in summer, and a 10 min increase in UV exposure time was necessary to increase 25(OH)D3 by 0.47 ng/mL. Although consideration of personal occupation and lifestyle is necessary, most Japanese may need to increase both vitamin D intake and UV exposure.


2020 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Jennifer B. Fields ◽  
Sina Gallo ◽  
Jenna M. Worswick ◽  
Deanna R. Busteed ◽  
Margaret T. Jones

Women athletes are at higher risk for bone diseases; yet, information on vitamin D status ((25(OH)D), vitamin D binding protein (VDBP), and bioavailable 25(OH)D is limited. Collegiate athletes (n = 36) from volleyball (WVB), basketball (WBB), and track and field (WTF) were measured for (25(OH)D), VDBP, and bioavailable 25(OH)D; body composition and bone mineral density (BMD); and skin pigmentation. Participants self-reported daily vitamin D intake and sun exposure. One-way analysis of variance analyzed mean differences in measures across sports. Linear regression examined relationships between 25(OH)D; VDBP; bioavailable 25(OH)D; and whole body, hip, and spine BMD. Participants’ (mean ± SD, 19.4 ± 1.4 years, 172.75 ± 8.21 cm, 70.9 ± 13.2 kg, and 22.9 ± 4.1% body fat) overall mean 25(OH)D was 70.5 ± 32.25 nmol/L, and 28% of participants were deemed inadequate and 61% below thresholds identified as sufficient for athletes. Although WBB athletes consumed higher (p = 0.007) dietary vitamin D (760.9 ± 484.2 IU/d) than WVB (342.6 ± 257.8) and WTF (402.3 ± 376.4) athletes did, there were no differences across sport in serum 25(OH)D. WVB and WTF had higher bioavailable 25(OH)D than WBB. No relationships existed between vitamin D status and body composition. Vitamin D inadequacy was identified among 1/3 of women indoor sport athletes. Consistent monitoring of vitamin D status and diet are recommended to sustain athlete health and sport performance.


2003 ◽  
Vol 88 (1) ◽  
pp. 185-191 ◽  
Author(s):  
Reinhold Vieth ◽  
Yasmin Ladak ◽  
Paul G. Walfish

Vitamin D requirements are thought to vary with age, but there is little comparative evidence for this. One goal in establishing a vitamin D requirement is to avoid secondary hyperparathyroidism. We studied 1741 euthyroid, thyroid clinic outpatients without evidence of calcium abnormalities, ranging in age from 19 to 97 yr, whose serum and urine had been analyzed for calcium, vitamin D, and parathyroid status. We found no effect of age on the 25-hydroxyvitamin D [25(OH)D] concentration associated with specific vitamin D intakes, and there was no relationship between 25(OH)D and 1,25hydroxyvitamin D [1,25(OH)2D]. In every age group, serum 1,25(OH)2D declined with increasing creatinine (P &lt; 0.001). What changed with age included creatinine, which correlated with 25(OH)D (r = 0.146, P &lt; 0.001) only in the youngest age group (19–50 yr) but not in the older age groups (P &gt; 0.1). Creatinine did not correlate with PTH in the youngest age group, but the relationship became significant as age increased (e.g. for the elderly, r = 0.365, P &lt; 0.001). Linear regression of log PTH vs. log 25(OH)D agreed with the natural shape of the relationship observed with scatterplot smoothing, and this showed no plateau in PTH as 25(OH)D increased. We compared PTH concentrations among age groups, based on 20 nmol/liter increments in 25(OH)D. Mean PTH in adults older than 70 yr was consistently higher than in adults younger than 50 yr (P &lt; 0.05 by ANOVA and Dunnett’s t test). PTH levels of the elderly who had 25(OH)D concentrations greater than 100 nmol/liter matched PTH of younger adults having 25(OH)D concentrations near 70 nmol/liter. This study shows that all age groups exhibit a high prevalence of 25(OH)D insufficiency and secondary hyperparathyroidism. Older adults are just as efficient in maintaining 25(OH)D, but they need more vitamin D to produce the higher 25(OH)D concentrations required to overcome the hyperparathyroidism associated with their diminishing renal function.


2008 ◽  
Vol 99 (6) ◽  
pp. 1330-1334 ◽  
Author(s):  
Jean Woo ◽  
Christopher W. K. Lam ◽  
Jason Leung ◽  
Winny Y. Lau ◽  
Edith Lau ◽  
...  

We aimed to describe the vitamin D status of young women living in two Chinese cities in the spring – Beijing in the north (latitude 39° north) and Hong Kong (latitude 22° north) in the south. We also examined the relationship between serum 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations to determine a threshold for serum 25-hydroxyvitamin D above which there is no further suppression of PTH. Finally, we examined whether dietary Ca intake influences this relationship. Non-pregnant women aged 18–40 years (n 441) were recruited between February and June. Fasting blood was collected and dietary intakes were assessed using 5 d food records. Mean serum 25-hydroxyvitamin D concentration was lower in Beijing than Hong Kong women (29 v. 34 nmol/l; P < 0·001). Vitamin D deficiency ( ≤  25 nmol/l) was indicated in 40 % of Beijing and 18 % of Hong Kong women, and over 90 % of women in both cities were insufficient ( ≤ 50 nmol/l). Mean Ca and vitamin D intakes were 478 mg/d and 2·0 μg/d, respectively. The relationship between 25-hydroxyvitamin D concentration and PTH was linear throughout the range with a slope of − 0·36 (different from 0; P < 0·001; R 0·26), with no apparent threshold. There was no influence of Ca intake on the relationship between 25-hydroxyvitamin D and PTH concentration. Vitamin D deficiency is common and insufficiency is very common in non-pregnant women in Hong Kong and Beijing during spring. Serum 25-hydroxyvitamin D was inversely associated with PTH with no apparent threshold. Strategies such as vitamin D fortification or supplementation may be required.


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