Clinical Characteristics and Follow-up Assessment in Patients Diagnosed With Alzheimer's Dementia Through Regional Dementia Centers and Conventional Hospital System.

BACKGROUND: The rapidly increasing socioeconomic strain caused by dementia represents a significant public health concern. Regional dementia centers (RDCs) have been established nationwide, and they aim to provide timely screening and diagnosis of dementia. This study investigated the clinical characteristics and progression of patients diagnosed with Alzheimer's dementia (AD), who underwent treatment in RDCs or conventional community-based hospital systems. METHODS: This retrospective single-center cohort study included patients who were diagnosed with AD between January 2019 and March 2022. This study compared two groups of patients: the hospital group, consisting of patients who presented directly to the hospital, and the RDC group, those who were referred to the hospital from the RDCs in Pohang city. The clinical courses of the patients were monitored for a year after AD diagnosis. RESULTS: A total of 1,209 participants were assigned to the hospital (n = 579) or RDC group (n = 630). The RDC group had a mean age of 80.1 years ± 6.6 years, which was significantly higher than that of the hospital group (P < 0.001). The RDC group had a higher proportion of females (38.3% vs. 31.9%; P = 0.022), higher risk for alcohol consumption (12.4% vs. 3.3%; P < 0.001), and greater number of patients who discontinued treatment 1 year after diagnosis (48.3% vs. 39.0%; P = 0.001). In the linear regression model, the RDC group was independently associated with the clinical dementia rating sum of boxes increment (ß = 22.360, R²\n = 0.048, and P < 0.001). CONCLUSION: Patients in the RDC group were older, had more advanced stages of conditions, and exhibited a more rapid rate of cognitive decline than patients diagnosed through the conventional hospital system. Our results suggested that RDC contributed to the screening of AD in a local region, and further nationwide study with the RDC database of various areas of Korea is needed.

Effects of Socioeconomic Status and Residence Areas on Long-Term Survival in Patients With Early-Onset Dementia: The Korean National Health Insurance Service Database Study.

BACKGROUND: Early-onset dementia (EOD) is still insufficiently considered for healthcare policies. We investigated the effect of socio-environmental factors on the long-term survival of patients with EOD. METHODS: This retrospective cohort study utilized the Korean National Health Insurance Database from 2007 to 2018. We enrolled 3,825 patients aged 40 to 65 years old with all types of dementia newly diagnosed in 2009 as EOD cases. We defined socioeconomic status using the national health insurance premium (NHIP) levels. Residential areas were classified into capital, metropolitan, city, and county levels. All-cause mortality was the primary outcome. Kaplan-Meier curves and log-rank tests were employed. Further, Cox-proportional hazards models were established. RESULTS: The mean survival of the fourth NHIP level group was 96.31 ± 1.20 months, whereas that of the medical-aid group was 85.53 ± 1.30 months (P < 0.001). The patients living in the capital had a mean survival of 95.73 ± 1.34 months, whereas those living in the county had 89.66 ± 1.75 months (P = 0.035). In the Cox-proportional hazards model, the medical-aid (adjusted hazard ratio [aHR], 1.67; P < 0.001), first NHIP level (aHR, 1.26; P = 0.012), and second NHIP level (aHR, 1.26; P = 0.008) groups were significantly associated with a higher long-term mortality risk. The capital residents exhibited a significantly lower long-term mortality risk than did the county residents (aHR, 0.82; P = 0.041). CONCLUSION: Socioeconomic status and residential area are associated with long-term survival in patients with EOD. This study provides a rational basis for establishing a healthcare policy for patients with EOD.

Behavioral and Disease-Related Characteristics of Patients with Acute Stroke during the Coronavirus Disease Pandemic.

This study aimed to evaluate the behavioral and disease-related characteristics of patients with acute stroke during the Coronavirus disease (COVID-19) pandemic. This retrospective study was conducted using the Korean Stroke Registry database from a single cerebrovascular specialty hospital. We categorized the COVID-19 pandemic (February 2020 to June 2021) into three waves according to the number of COVID-19 cases recorded and the subjective fear index of the general population and matched them with the corresponding pre-COVID-19 (January 2019 to January 2020) periods. The total number of acute stroke hospitalizations during the pre-COVID-19 and COVID-19 periods was 402 and 379, respectively. The number of acute stroke hospitalizations recorded during the regional outbreak of COVID-19 was higher than that recorded during the corresponding pre-COVID-19 period (97 vs. 80). Length of hospital stay was significantly longer during the COVID-19 pandemic than during the pre-COVID-19 period (11.1 and 8.5 days, respectively; p = 0.003). There were no significant differences in the time from onset to hospital arrival, rate of acute intravenous/intra-arterial (IV/IA) treatments, and door-to-IV/IA times between the pre-COVID-19 and COVID-19 periods. This study suggests that specialty hospitals can effectively maintain the quality of healthcare through the management of acute time-dependent diseases, even during pandemics.

Awareness, intentions and attitudes towards planned oocyte cryopreservation among female medical staff.

RESEARCH QUESTION: What are the awareness, intentions and attitudes of female medical staff towards planned oocyte cryopreservation? DESIGN: A cross-sectional survey was conducted during June 2019 among 171 female medical staff at a single tertiary hospital. The self-administered questionnaire consisted of 39 questions. RESULTS: A total of 151 responses (88%) were received from 13 doctors and 138 nurses. The mean age of the respondents was 26.4 years. Fewer than half of the women (47.7%) answered correctly on the age at which female fertility markedly declines. The study demonstrated that 28.5% of respondents considered themselves as 'potential freezers' while 30.5% would not consider the procedure. Potential freezers (58.1% versus 21.7%, P < 0.001) and older age participants (44.2% versus 28.4, P = 0.014) were more interested in consulting about fertility preservation during an obstetrician/gynaecologist (OB/GYN) visit. If respondents were to consider oocyte cryopreservation, they thought that lack of information would be a major obstacle to accepting the procedure (57.6%). Of the respondents, 85.3% believed that oocyte cryopreservation is a woman's right. A strong majority of respondents (96.0%) agreed or were neutral on the statement that all women have the right to receive education on fertility preservation during OB/GYN visits, but none had ever received medical education about fertility preservation, reflecting lack of access to fertility preservation care. CONCLUSIONS: This study indicated that there was widespread awareness about planned oocyte cryopreservation among female medical staff. The majority of participants considered planned oocyte cryopreservation as a woman's right. There appears to be a critical need for proper education about fertility preservation.

The effects of socioeconomic and geographic factors on chronic phase long-term survival after stroke in South Korea.

The stroke incidence has increased rapidly in South Korea, calling for a national-wide system for long-term stroke management. We investigated the effects of socioeconomic status (SES) and geographic factors on chronic phase survival after stroke. We retrospectively enrolled 6994 patients who experienced a stroke event in 2009 from the Korean National Health Insurance database. We followed them up from 24 to 120 months after stroke onset. The endpoint was all-cause mortality. We defined SES using a medical-aid group and four groups divided by health insurance premium quartiles. Geographic factors were defined using Model 1 (capital, metropolitan, city, and county) and Model 2 (with or without university hospitals). The higher the insurance premium, the higher the survival rate tended to be (P < 0.001). The patient survival rate was highest in the capital city and lowest at the county level (P < 0.001). Regions with a university hospital(s) showed a higher survival rate (P = 0.006). Cox regression revealed that the medical-aid group was identified as an independent risk factor for chronic phase mortality. Further, NHIP level had a more significant effect than geographic factors on chronic stroke mortality. From these results, long-term nationwide efforts to reduce inter-regional as well as SES discrepancies affecting stroke management are needed.

Changes in Stroke Patients' Health-Seeking Behavior by COVID-19 Epidemic Regions: Data from the Korean Stroke Registry.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic has led to changes in stroke patients' healthcare use. This study evaluated changes in Korean stroke patients' health-seeking behaviors and stroke care services using data from the Korean Stroke Registry (KSR). METHODS: We reviewed data from patients with acute stroke and transient ischemic attack (TIA) during 2019 (before COVID-19 period) and 2020 (COVID-19 period). Outcomes included patient characteristics, time from stroke onset to hospital arrival, and in-hospital stroke pathways. Subgroup analyses were performed for an epidemic region (Daegu city and Gyeongsangbuk-do region, the D-G region). RESULTS: The study included 1,792 patients from the pre-COVID-19 period and 1,555 patients from the COVID-19 period who visited hospitals that contribute to the KSR. During the COVID-19 period, the D-G region had two-thirds the number of cases (vs. the pre-CO-VID-19 period) and a significant decrease in the proportion of patients with TIA (9.97%-2.91%). Unlike other regions, the median onset-to-door time increased significantly in the D-G region (361 min vs. 526.5 min, p = 0.016), and longer onset-to-door times were common for patients with mild symptoms and who were in their 60s or 70s. The number of patients who underwent intravenous thrombolysis also decreased during the COVID-19 period, although the treatment times were not significantly different between the 2 periods. DISCUSSION/CONCLUSION: Korean stroke patients in a CO-VID-19 epidemic region exhibited distinct changes in health-seeking behaviors. Appropriate triage system and public education regarding the importance of early treatment are needed during the COVID-19 pandemic.

Machine Learning-Based Three-Month Outcome Prediction in Acute Ischemic Stroke: A Single Cerebrovascular-Specialty Hospital Study in South Korea.

BACKGROUND: Functional outcomes after acute ischemic stroke are of great concern to patients and their families, as well as physicians and surgeons who make the clinical decisions. We developed machine learning (ML)-based functional outcome prediction models in acute ischemic stroke. METHODS: This retrospective study used a prospective cohort database. A total of 1066 patients with acute ischemic stroke between January 2019 and March 2021 were included. Variables such as demographic factors, stroke-related factors, laboratory findings, and comorbidities were utilized at the time of admission. Five ML algorithms were applied to predict a favorable functional outcome (modified Rankin Scale 0 or 1) at 3 months after stroke onset. RESULTS: Regularized logistic regression showed the best performance with an area under the receiver operating characteristic curve (AUC) of 0.86. Support vector machines represented the second-highest AUC of 0.85 with the highest F1-score of 0.86, and finally, all ML models applied achieved an AUC > 0.8. The National Institute of Health Stroke Scale at admission and age were consistently the top two important variables for generalized logistic regression, random forest, and extreme gradient boosting models. CONCLUSIONS: ML-based functional outcome prediction models for acute ischemic stroke were validated and proven to be readily applicable and useful.

Usefulness of Intraoperative Neurophysiological Monitoring During the Clipping of Unruptured Intracranial Aneurysm: Diagnostic Efficacy and Detailed Protocol.

Background: Intraoperative neurophysiological monitoring (IONM) has been widely applied in brain vascular surgeries to reduce postoperative neurologic deficit (PND). This study aimed to investigate the effect of IONM during clipping of unruptured intracranial aneurysms (UIAs). Methods: Between January 2013 and August 2020, we enrolled 193 patients with 202 UIAs in the N group (clipping without IONM) and 319 patients with 343 UIAs in the M group (clipping with IONM). Patients in the M group were intraoperatively monitored for motor evoked potentials (MEPs) and somatosensory evoked potentials (SSEPs). Irreversible evoked potential (EP) change was defined as EP deterioration that did not recover until surgery completion. Sustained PND was defined as neurological symptoms lasting for more than one postoperative month. Results: Ten (3.1%) and 13 (6.7%) in the M and N groups, respectively, presented with PND. Compared with the N group, the M group had significantly lower occurrence rates of sustained PND [odds ratio (OR) = 0.36, 95% confidence interval (CI) = 0.13-0.98, p = 0.04], ischemic complications (OR = 0.39, 95% CI = 0.15-0.98, p = 0.04), and radiologic complications (OR = 0.40, 95% CI = 0.19-0.82, p = 0.01). Temporary clipping was an independent risk factor for ischemic complications (ICs) in the total patient group (OR = 6.18, 95% CI = 1.75-21.83, p = 0.005), but not in the M group (OR = 5.53, 95% CI = 0.76-41.92, p = 0.09). Regarding PND prediction, considering any EP changes (MEP and/or SSEP) showed the best diagnostic efficiency with a sensitivity of 0.900, specificity of 0.940, positive predictive value of 0.321, negative predictive value (NPV) of 0.997, and a negative likelihood ratio (LR) of 0.11. Conclusion: IONM application during UIA clipping can reduce PND and radiological complications. The diagnostic effectiveness of IONM, specifically the NPV and LR negative values, was optimal upon consideration of changes in any EP modality.

Disparities in the Diagnosis, Treatment, and Survival Rate of Cervical Cancer among Women with and without Disabilities.

INTRODUCTION: Not much is known regarding the disparities in cancer care between women with and without disabilities. OBJECTIVES: The aim of this study was to investigate the potential disparities in the diagnosis, treatment, and survival of women with cervical cancer with and without disabilities. METHODS: We performed a retrospective cohort study and linked the National Disability Database, Korean Central Cancer Registry, and Korean National Health Insurance claims database. Charlson comorbidity index was used for adjusting the comorbidity. The study population comprised 3 185 women with disabilities (physical/brain, communication, mental, cardiopulmonary, and other impairment) who were diagnosed with cervical cancer and 13 582 age- and sex-matched women without disability who were diagnosed with cervical cancer for comparison. RESULTS: Distant metastatic stage (7.7% vs 3.7%) and unknown stage (16.1% vs 7.0%) were more common in cervical cancer women with grade 1 disabilities, compared with women without disabilities. Women with cervical cancer with disabilities were less likely to undergo surgery (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.73-0.90) or chemotherapy (aOR 0.86, 95% CI 0.77-0.97). Lower rate of surgery was more evident in patients with physical/brain impairment (aOR 0.46, 95% CI 0.37-0.58) and severe mental impairment (aOR 0.57, 95% CI 0.41-0.81). The overall mortality risk was also higher in patients with disabilities (adjusted hazard ratio (aHR) 1.36, 95% CI 1.25-1.48). CONCLUSION: Women with cervical cancer with disabilities, especially with severe disabilities, were diagnosed at later stages, received less treatment, and had higher mortality rates, compared with patients who lacked disabilities. Social support and policies, along with education for women with disabilities, their families, and healthcare professionals, are needed to improve these disparities.

Active Hexose Correlated Compound (AHCC) Inhibits the Proliferation of Ovarian Cancer Cells by Suppressing Signal Transducer and Activator of Transcription 3 (STAT3) Activation.

The purpose of this study was to investigate the antiproliferative effect of active hexose correlated compound (AHCC), derived from basidiomycete mushroom culture, on ovarian cancer cell lines. An in vitro growth inhibition assay was performed using AHCC in ovarian cancer cell lines. Western blotting was performed to investigate the mechanism of the observed antiproliferative effect of AHCC. We identified that ovarian cancer cell viability was significantly reduced through treatment with AHCC compared to that in the control. AHCC inhibited constitutive signal transducer and activator of transcription 3 (STAT3) phosphorylation in ovarian cancer cell lines. In contrast, treatment with pervanadate, a protein tyrosine phosphatase inhibitor, reversed AHCC-induced STAT3 suppression. AHCC treatment induced the expression of SHP-1, a protein tyrosine phosphatase, and suppressed the expression of cyclin D1, Bcl-2, Mcl-1, survivin, and VEGF, which are STAT3-regulated gene products that are associated with cell proliferation or apoptosis. These results suggest that AHCC has an antiproliferative effect on ovarian cancer cell lines, via STAT3 phosphorylation; thus, this compound has the potential to be a complementary and alternative anticancer therapy for the treatment of ovarian cancer.

Delayed postpartum hemoperitoneum due to uterine artery pseudoaneurysm rupture.

A 30-year-old woman experienced severe abdominal pain 8 days after vaginal delivery. The patient was diagnosed with hemoperitoneum due to rupture of the left uterine artery pseudoaneurysm, which was confirmed via ultrasound with color Doppler and computed tomography scans. This patient was treated with bilateral uterine artery embolization to maintain fertility. A uterine artery pseudoaneurysm that causes delayed postpartum hemorrhage can occur after cesarean section or vaginal delivery. A uterine artery pseudoaneurysm can be fatal, so its detection and diagnosis are critical. Herein, we report a case of delayed postpartum hemoperitoneum due to uterine artery pseudoaneurysm rupture.

A case of spontaneous hemoperitoneum by uterine vessel rupture in pregnancy.

A 27-year-old pregnant woman, para 1, was transferred to our hospital at 29+3 weeks of gestation complaining of abdominal pain. She was diagnosed with hemoperitoneum based on ultrasonography. An emergency laparotomy was performed, and the bleeding was confirmed to be caused by ruptured surface blood vessels on the uterine fundus. Hemostasis with compression was successfully performed to sustain the pregnancy, and the patient delivered a full-term baby. Spontaneous hemoperitoneum during pregnancy caused by rupture of uterine blood vessels is very rare. It requires rapid diagnosis and surgical treatment because it increases the morbidity of the fetus and mother. In most incidences of spontaneous hemoperitoneum during pregnancy, a cesarean delivery is performed along with a simultaneous emergency laparotomy. However, in this case, the pregnancy was maintained to full term after surgical hemostasis, which prevented neonatal complications due to premature birth.

Myometrial relaxation of mice via expression of two pore domain acid sensitive K(+) (TASK-2) channels.

Myometrial relaxation of mouse via expression of two-pore domain acid sensitive (TASK) channels was studied. In our previous report, we suggested that two-pore domain acid-sensing K(+) channels (TASK-2) might be one of the candidates for the regulation of uterine circular smooth muscles in mice. In this study, we tried to show the mechanisms of relaxation via TASK-2 channels in marine myometrium. Isometric contraction measurements and patch clamp technique were used to verify TASK conductance in murine myometrium. Western blot and immunehistochemical study under confocal microscopy were used to investigate molecular identity of TASK channel. In this study, we showed that TEA and 4-AP insensitive non-inactivating outward K(+) current (NIOK) may be responsible for the quiescence of murine pregnant longitudinal myometrium. The characteristics of NIOK coincided with two-pore domain acid-sensing K(+) channels (TASK-2). NIOK in the presence of K(+) channel blockers was inhibited further by TASK inhibitors such as quinidine, bupivacaine, lidocaine, and extracellular acidosis. Furthermore, oxytocin and estrogen inhibited NIOK in pregnant myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed stronger inhibition of NIOK by quinidine and increased immunohistochemical expression of TASK-2. Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretch-activated channels in the longitudinal myometrium of mouse. Activation of TASK-2 channels seems to play an essential role for relaxing uterus during pregnancy and it might be one of the alternatives for preventing preterm delivery.

Regulation of myometrial contraction by ATP-sensitive potassium (KATP) channel via activation of SUR2B and Kir 6.2 in mouse.

ATP-sensitive potassium (KATP) channels are well characterized in cardiac, pancreatic and many other muscle cells. In the present study, functional expression of the KATP channel was examined in non-pregnant murine longitudinal myometrium. Isometric contraction measurements and Western blot were used. KATP channel openers (KCOs), such as pinacidil, cromakalim, diazoxide and nicorandil, inhibited spontaneous myometrial contractions in a reversible and glibenclamide-sensitive manner. KCOs inhibited oxytocin (OXT)- and prostaglandin F2α (PGF2α)-induced phasic contractions in a glibenclamide-sensitive manner. SUR2B and Kir6.2 were detected by Western blot, whereas SUR1, SUR2A and Kir6.1 were not. These results show that pinacidl, cromakalim, diazoxide and nicorandil-sensitive KATP channels exist in murine myometrium, which are composed of SUR2B and Kir6.2. Based on the modulatory effects of the KATP channel on spontaneous contraction, OXT- and PGF2α-induced contractions, KATP channels seem to play an essential role in murine myometrial motility via activation of SUR2B and Kir6.2.

Safety of cesarean delivery through placental incision in patients with anterior placenta previa.

OBJECTIVE: To demonstrate the safety of fetal delivery through placental incision in a placenta previa pregnancy. METHODS: We examined the medical records of 80 women with singleton pregnancy diagnosed with placenta previa who underwent cesarean section between May 2010 and May 2015 at the Department of Obstetrics and Gynecology, Chungbuk National University Hospital. Among the women with placenta previa, those who did not have the placenta in the uterine incision site gave birth via conventional uterine incision, while those with anterior placenta previa or had placenta attached to the uterine incision site gave birth via uterine incision plus placental incision. We compared the postoperative hemoglobin level and duration of hospital stay for the mother and newborn of the two groups. RESULTS: There was no difference between the placental incision group and non-incision group in terms of preoperative and postoperative hemoglobin change, the amount of blood transfusions required by the mother, newborns with 1-min or 5-min Apgar scores below 7 points or showing signs of acidosis on umbilical cord blood gas analysis result of pH below 7.20. Moreover, neonatal hemoglobin levels did not differ between the two groups. CONCLUSION: Fetal delivery through placental incision during cesarean section for placenta previa pregnancy does not negatively influence the prognosis of the mother or the newborn, and therefore, is considered a safe surgical technique.

Increased Nuchal Translucency and Early Growth Retardation Related to Confined Placental Mosaicism of Trisomy 16 in a Dichorionic Twin.

Confined placental mosaicism (CPM) of trisomy 16 is related to intrauterine growth restriction; however, its association with increased nuchal translucency (NT) has not been sufficiently studied. We report the first case involving a diagnosis of CPM for trisomy 16 in a dichorionic twin. Increased NT (3.7 mm) and 1 week of growth retardation at 12 weeks of gestational age were detected in the affected fetus compared with the normal fetus. Given that the biochemical analytes in maternal serum aneuploidy screening of the abnormal fetus were diluted by the presence of the normal fetus, this method was unreliable as a screening tool. Therefore, in dichorionic twins, ultrasonographic findings such as increased NT and early growth retardation can serve as important indicators for the diagnosis of CPM of trisomy 16.

Mixed gonadal dysgenesis in 45,X Turner syndrome with SRY gene.

Turner syndrome is the most common chromosomal disorder in girls. Various phenotypic features show depending upon karyotype from normal female through ambiguous genitalia to male. Usually, Turner girls containing 45,X/46,XY mosaicism, or sex-determining region Y (SRY) gene may have mixed gonadal dysgenesis with various external sexual differentiation. We experienced a short statured 45,X Turner girl with normal external genitalia. Because SRY gene was positive, laparoscopic gonadectomy was performed. The dysgenetic gonads revealed bilateral ovotesticular tissues. The authors report a mixed gonadal dysgenesis case found in clinical 45,X Turner patient with positive SRY gene. Screening for SRY gene should be done even the karyotype is 45,X monosomy and external genitalia is normal.

Temporary homonymous hemianopsia after epidural blood patch.

We describe a case in which homonymous hemianopsia developed abruptly following an epidural blood patch procedure. The procedure was performed in a patient complaining of post-dural puncture headache after an emergency Cesarean section under spinal anesthesia. Computed tomography and magnetic resonance imaging demonstrated that air bubbles had moved from the prepontine and premedullar cisterns toward the left retrochiasmal region. The homonymous hemianopsia resolved rapidly with conservative management including oxygen, intravenous fluid, and antibiotics. We report on this case with a brief review of the related literature.

Laparoscopic appendectomy is a safe and beneficial procedure in pregnant women.

BACKGROUND: Appendectomy is the most common nongynecologic surgery performed during pregnancy. Pregnancy is no longer considered an absolute contraindication for laparoscopic procedures. Laparoscopic appendectomy (LA) is a safe, effective, and beneficial procedure for the treatment of acute appendicitis. However, limited data are available regarding the safety and feasibility of LA during pregnancy. METHODS: Between May 2005 and May 2009, 20 patients with clinically suspected appendicitis in pregnancy underwent LA at Chungbuk National University Hospital. Clinical data collected retrospectively included demographic information. We compared maternal age, gestational age, operation time, anesthetic time, surgical complications, length of hospitalization, and final outcome of pregnancy. RESULTS: All the 20 patients who underwent LA did not need a conversion. Mean maternal age was 28.1 years (range, approximately 20 to 35 y), gestational age was 15.4 weeks (range, approximately 6 to 30 wk), mean operation time was 45.5 minutes (range, approximately 25 to 90 min), mean length of hospital stay was 4.7 days (range, approximately 2 to 11 d). Fifteen of 20 pregnant women delivered healthy term infants and 5 women have kept a healthy pregnancy. CONCLUSIONS: Our data support the accumulating evidence that LA is a safe and feasible procedure for the treatment of acute appendicitis in all trimesters of pregnancy. Close maternal and fetal monitoring is essential during and after the operation.

Nutritional status of vitamin D and the effect of vitamin D supplementation in Korean breast-fed infants.

We investigated the vitamin D status and the effect of vitamin D supplementation in Korean breast-fed infants. The healthy term newborns were divided into 3 groups; A, formula-fed; B, breast-fed only; S, breast-fed with vitamin D supplementation. We measured serum concentrations of vitamin D (25OHD3), calcium (Ca), phosphorus (P), alkaline phosphatase (AP), intact parathyroid hormone (iPTH) and bone mineral density (BMD) at 6 and 12 months of age. Using questionnaires, average duration of sun-light exposure and dietary intake of vitamin D, Ca and P were obtained. At 6 and 12 months of age, 25OHD3 was significantly higher in group S than in group B (P<0.001). iPTH was significantly lower in group S than in group B at 6 months (P=0.001), but did not differ at 12 months. Regardless of vitamin D supplementation, BMD was lower in group B and S than in group A (P<0.05). Total intake of vitamin D differed among 3 groups (P<0.001, A>S>B), but total intake of Ca and P were higher in group A than in group B and S (P<0.001). In conclusion, breast-fed infants show lower vitamin D status and bone mineralization than formula-fed infants. Vitamin D supplementation (200 IU/day) in breast-fed infants increases serum 25-OH vitamin D(3), but not bone mineral density.