• Clinical and Experimental Pediatrics
• /
• v.58 no.11
• /
• pp.427-433
• /
• 2015

Purpose: We investigated the vitamin D status of preterm infants to determine the incidence of vitamin D deficiency. Methods: A total of 278 preterm infants delivered at Kyungpook National University Hospital between January 2013 and May 2015 were enrolled. The serum concentrations of calcium, phosphorous, alkaline phosphatase, and 25-hydroxyvitamin D (25-OHD) were measured at birth. We collected maternal and neonatal data such as maternal gestational diabetes, premature rupture of membranes, maternal preeclampsia, birth date, gestational age, and birth weight. Results: Mean gestational age was $33^{+5}{\pm}2^{+2}$ weeks of gestation and mean 25-OHD concentrations were $10.7{\pm}6.4ng/mL$. The incidence of vitamin D deficiency was 91.7%, and 51.1% of preterm infants were classified as having severe vitamin D deficiency (25-OHD<10 ng/mL). The serum 25-OHD concentrations did not correlate with gestational age. There were no significant differences in serum 25-OHD concentrations or incidence of severe vitamin D deficiency among early, moderate, and late preterm infants. The risk of severe vitamin D deficiency in twin preterm infants was significantly higher than that in singletons (odds ratio, 1.993; 95% confidence interval [CI], 1.137-3.494, P=0.016). In the fall, the incidence of severe vitamin D deficiency decreased 0.46 times compared to that in winter (95% CI, 0.227-0.901; P=0.024). Conclusion: Most of preterm infants (98.9%) had vitamin D insufficiency and half of them were severely vitamin D deficient. Younger gestational age did not increase the risk of vitamin D deficiency, but gestational number was associated with severe vitamin D deficiency.

• Korean Journal of Community Nutrition
• /
• v.19 no.2
• /
• pp.122-132
• /
• 2014

Objectives: This study was conducted to investigate the vitamin D status and to determine the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and consumption frequencies of vitamin D rich foods in Korean adults and older adults. Methods: Subjects were 10,374 adults and 2,792 older adults participating in the 2008-2009 Korea National Health and Nutrition Examination Survey (KNHANES). Consumption frequencies of vitamin D rich foods were estimated by using a qualitative food frequency questionnaire (FFQ). Eleven food items such as beef, egg, mackerel, tuna, yellow corvina, pollack, anchovy, mushroom, milk, yogurt, and ice cream were selected as vitamin D rich foods based on previous research. Results: The proportions of deficiency (< 12 ng/mL), inadequacy (12-20 ng/mL) and sufficiency (${\geq}20ng/mL$) of serum 25(OH)D concentrations from June to November and December to May in adults were 8.8%, 42.3%, 48.8%, and 28.2%, 52.8%, 19.1%, respectively. The proportions of deficiency, inadequacy and sufficiency of serum 25(OH)D concentrations from June to November and December to May in older adults were 10.1%, 32.4%, 57.5%, and 24.1%, 45.4%, 30.5%, respectively. The mean serum 25(OH)D concentrations in adults were positively related to the consumption frequencies of mackerel, anchovy, all fish, milk and milk dairy products. The mean serum 25(OH)D concentrations in older adults were positively related to the consumption frequencies of yellow corvina and negatively related to the consumption frequencies of ice cream. Conclusions: Our results suggest that Korean adults were more deficient in serum 25(OH)D concentrations than older adults. The consumption of vitamin D rich foods may affect vitamin D status in Korean adults. Further studies are required to confirm these findings.

• Preventive Nutrition and Food Science
• /
• v.1 no.1
• /
• pp.80-86
• /
• 1996

Parathyroid hormone(PTH) is known to stimulate bone resorption and to inhibit bone collagen synthesis. In contrast, as the evidence of stimulation of bone formation by PTH has recently been observed, the study on the role of PTH involved in osteoporosis draws remarkable attention. This study has dealt with the role of alkaline phoshatase(AP), a marker enzyme for bone formation and osteoblast action, Animals(BALS/cmice) were divided into three dietary groups(high and medium Ca and Ca-free) and hormones including PTH, calcitonin(CT), cholecalciferol(citamin D) were i.p. injected. AP in the serum and liver was measured using Sigma 221 alkaline buffer solutions containing 9mM of p-nitrophenyl phoshate. Enzume was reacted at 37$^{\circ}C$ for 10 minutes and the reaction was stopped by 1.8ml of 0.1N NaOH and measured at 410nm. We found that serum and liver AP activity was increased by low dietary Ac. Compared to the control, and serum Ap activity was enhanced by PTH and vitamin D regardless of the dietary Ca. On the other hand, liver AP activity was inhibited by OTH and vitamin D at all levels of dietary Ca. CT inhibited the action of PTH and vitamin D in the serum. But, the inhibition of PTH and vitamin D action by CT was not observed in the liver, unlike in the case of serum.

• Nutrition Research and Practice
• /
• v.15 no.3
• /
• pp.329-345
• /
• 2021

BACKGROUD/OBJECTIVES: Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies. MATERIALS/METHODS: Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I² statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis. RESULTS: The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76-0.84; I² = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72-0.98; I² = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS. CONCLUSIONS: Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

• Korean Journal of Community Nutrition
• /
• v.10 no.1
• /
• pp.79-90
• /
• 2005

This study was performed to estimate serum 25-hydroxyvitamin D level and to evaluate the relationship between serum 2S-hydroxyvitamin D level and associated factors. The subjects were 61 premenopausal working women aged 30 - 49 y in Busan. The serum 25-hydroxyvitamin D level was measured by radioimmunoassay. Data for physiological characteristics, lifestyle factors, physical activity and nutrient intake were assessed by questionnaire including information about outdoor activity time, daily activity diary and 24 hr recall method. The mean vitamin D intake was 3.12 ug, which corresponded to $62.5\%$ of the Korean RDA. The mean level of serum 25-hydroxyvitamin D was 31.0 ng/mL. Low 25-hydroxyvitamin D (<25 nmol/L) was not found in the subjects. The serum 2S-hydroxyvitamin D level showed positive significant correlations with exercise hours, daily energy expenditure, hours of outdoor activity per weekdays (p < 0.001, P < 0.05, P < 0.05). Exercise hours were found to be the most important determinant of serum 25-hydroxyvitamin D level. Therefore nutritional education for increasing hours of physical activity including indoor and outdoor exercise, is needed for premenopausal working women to increase vitamin D status.

• Clinical and Experimental Pediatrics
• /
• v.54 no.2
• /
• pp.51-54
• /
• 2011

Vitamin D is present in two forms, ergocalciferol (vitamin $D_2$) produced by plants and cholecalciferol (vitamin $D_3$) produced by animal tissues or by the action of ultraviolet light on 7-dehydrocholesterol in human skin. Both forms of vitamin D are biologically inactive pro-hormones that must undergo sequential hydroxylations in the liver and the kidney before they can bind to and activate the vitamin D receptor. The hormonally active form of vitamin D, 1,25-dihydroxyvitamin D3 $[1,25(OH)_2D]$, plays an essential role in calcium and phosphate metabolism, bone growth, and cellular differentiation. Renal synthesis of $1,25(OH)_2D$ from its endogenous precursor, 25-hydroxyvitamin D (25OHD), is the rate-limiting and is catalyzed by the $1{\alpha}$-hydroxylase. Vitamin D dependent rickets type I (VDDR-I), also referred to as vitamin D $1{\alpha}$-hydroxylase deficiency or pseudovitamin D deficiency rickets, is an autosomal recessive disorder characterized clinically by hypotonia, muscle weakness, growth failure, hypocalcemic seizures in early infancy, and radiographic findings of rickets. Characteristic laboratory features are hypocalcemia, increased serum concentrations of parathyroid hormone (PTH), and low or undetectable serum concentrations of $1,25(OH)_2D$ despite normal or increased concentrations of 25OHD. Recent advances have showed in the cloning of the human $1{\alpha}$-hydroxylase and revealed mutations in its gene that cause VDDR-I. This review presents the biology of vitamin D, and $1{\alpha}$-hydroxylase mutations with clinical findings.

• Nutrition Research and Practice
• /
• v.6 no.1
• /
• pp.86-90
• /
• 2012

This study assessed the association between vitamin D sufficiency (serum 25(OH)D ${\geq}30ng/mL$) and alcohol consumption using data from the Korea National Health and Nutrition Examination Survey conducted in 2009. The following characteristics were obtained in 7,010 Korean participants ${\geq}19$-years-of-age: serum 25(OH)D level, alcohol consumption (drinking frequency, drinking number of alcoholic beverages on a typical occasion, average daily-alcohol intake), and potential confounders (age, residence, housing status, occupation, total fat and lean mass, smoking, physical activity, history of liver diseases, liver function, and daily intake of energy, protein, and calcium). After adjusting for confounders, vitamin D sufficiency in men was significantly associated with drinking frequency, number of alcoholic drinks consumed, and average daily alcohol intake; odds ratio of 1.21-1.72, 2.17-3.04, and 2.27-3.09, respectively. Increase in the three alcohol drinking-related behaviors was also linearly associated with increase in serum 25(OH)D level in men. By comparison, there was no significant association between alcohol intake and serum 25(OH)D level in women. The positive association between vitamin D sufficiency and alcohol consumption was evident only in Korean men.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.1
• /
• pp.129-132
• /
• 2014

Background: The true association between breast cancer and vitamin D is currently under investigation. We compared serum 25-hydroxy-vitamin D levels in women with benign and malignant breast masses and controls. Materials and Methods: Levels of vitamin D were measured by electrochemiluminescense. Serum levels >35 ng/ml, 25-35 ng/ml, 12.5-25 ng/ml and <12.5 ng/ml were considered as normal, mild, moderate and severe vitamin D deficiency, respectively. Results: Overall, 364 women were included in the control, 172 in the benign and 136 in the malignant groups. The median serum vitamin D level was significantly lower in breast cancers than controls. Levels were also lower in malignant than benign cases and in benign cases than controls although statistically non-significant. Conclusions: Multinomial logistic regression analysis showed that severe vitamin D deficiency causes a three-fold increase in the risk of breast cancer while this was not the case for moderate and mild deficiency.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.20 no.1
• /
• pp.41-46
• /
• 2017

Purpose: Vitamin D deficiency is common in Crohn disease (CD). The aim of the study was to examine the prevalence of vitamin D deficiency and evaluate the association between vitamin D status and growth outcome in Korean pediatric CD patients. Methods: In this retrospective study, 17 children younger than 18 years old diagnosed with CD were enrolled and their serum 25-hydroxy vitamin D (25[OH]D) was checked between 2011 and 2015. We categorized the patients into two groups, Group 1 and Group 2. Group 1 included patients with serum 25(OH)D levels below 10 ng/mL, and Group 2 was for patients with a 25(OH)D serum levels between 10 ng/mL and 30 ng/mL. The z-scores for height (Htz), weight (Wtz), and body mass index (BMIz) were measured at baseline, 6 months, and 12 months. Results: The mean serum 25(OH)D levels of the total 65 CD patients and 17 enrolled patients were $15.64{\pm}6.9ng/mL$ and $13.1{\pm}5.1ng/mL$, respectively. There was no correlation at the beginning of the study between vitamin D level and growth parameters (Htz, Wtz, BMIz) or other variables including laboratory data and Pediatric Crohn Disease Activity Index. The Htz, Wtz, and BMIz in Group 1 showed no significant improvement at 6 months and 12 months follow-up. In Group 2, Wtz and BMIz showed significant improvements sustained until 12 months of follow-up. Htz showed no significant improvement at 6 months but there was significant improvement at 12 months. Conclusion: It seems that baseline vitamin D status affects growth outcome in pediatric CD.

• Journal of Medicine and Life Science
• /
• v.16 no.1
• /
• pp.31-33
• /
• 2019

Hypercalcemia is often seen in patients, but most of them showed mild to moderate hypercalcemia. The severe hypercalcemia with a blood calcium level of 14.0 mg/dL or more is known to be associated mainly with malignant tumors. Because this is emergency status, most clinicians tried to decrease serum calcium level to near normal range to improve symptoms related to hypercalcemia. A 71-year-old female patient visited the emergency room with dizziness and general weakness. Her serum calcium level was very high (15.6 mg/dL), but serum PTH, 25-OH vitamin D, and PTH related peptide were normal. We can exclude hyperparathyroidism, familial hypocalciuric hypercalcemia, other connective tissue diseases, and hypercalcemia due to malignant tumors as a cause of severe hypercalcemia. Conclusively, we diagnosed as severe hypercalcemia due to high-dose vitamin D injections treated one week ago. High dose vitamin D injections have recently been shown to increase the frequency of prescription as the various causes and the clinicians needed to carefully monitor the serum calcium levels in the patients after treating with high dose vitamin D.