The Importance of Body Weight for the Dose Response Relationship of Oral Vitamin D Supplementation and Serum 25-Hydroxyvitamin D in Healthy Volunteers

Unlike vitamin D recommendations by the Institute of Medicine, the Clinical Practice Guidelines by the Endocrine Society acknowledge body weight differentials and recommend obese subjects be given two to three times more vitamin D to satisfy their body's vitamin D requirement. However, the Endocrine Society also acknowledges that there are no good studies that clearly justify this. In this study we examined the combined effect of vitamin D supplementation and body weight on serum 25-hydroxyvitamin (25(OH)D) and serum calcium in healthy volunteers. We analyzed 22,214 recordings of vitamin D supplement use and serum 25(OH)D from 17,614 healthy adult volunteers participating in a preventive health program. This program encourages the use of vitamin D supplementation and monitors its use and serum 25(OH)D and serum calcium levels. Participants reported vitamin D supplementation ranging from 0 to 55,000 IU per day and had serum 25(OH)D levels ranging from 10.1 to 394 nmol/L. The dose response relationship between vitamin D supplementation and serum 25(OH)D followed an exponential curve. On average, serum 25(OH)D increased by 12.0 nmol/L per 1,000 IU in the supplementation interval of 0 to 1,000 IU per day and by 1.1 nmol/L per 1,000 IU in the supplementation interval of 15,000 to 20,000 IU per day. BMI, relative to absolute body weight, was found to be the better determinant of 25(OH)D. Relative to normal weight subjects, obese and overweight participants had serum 25(OH)D that were on average 19.8 nmol/L and 8.0 nmol/L lower, respectively (P<0.001). We did not observe any increase in the risk for hypercalcemia with increasing vitamin D supplementation. We recommend vitamin D supplementation be 2 to 3 times higher for obese subjects and 1.5 times higher for overweight subjects relative to normal weight subjects. This observational study provides body weight specific recommendations to achieve 25(OH)D targets

Insecticide-Treated Nets for the Prevention of Malaria in Pregnancy: A Systematic Review of Randomised Controlled Trials

BACKGROUND: Protection from malaria with insecticide-treated bednets (ITNs) during pregnancy is widely advocated, but evidence of benefit has been inconsistent. We undertook a systematic review of randomised trials. METHODS AND FINDINGS: Three cluster-randomised and two individually randomised trials met the inclusion criteria; four from Africa (n = 6,418) and one from Thailand (n = 223). In Africa, ITNs compared to no nets increased mean birth weight by 55 g (95% confidence interval [CI] 21–88), reduced low birth weight by 23% (relative risk [RR] 0.77, 95% CI 0.61–0.98), and reduced miscarriages/stillbirths by 33% (RR 0.67, 0.47–0.97) in the first few pregnancies. Placental parasitaemia was reduced by 23% in all gravidae (RR 0.77, 0.66–0.90). The effects were apparent in the cluster-randomised trials and the one individually randomised trial in Africa. The trial in Thailand, which randomised individuals to ITNs or untreated nets, showed reductions in anaemia and fetal loss in all gravidae, but not reductions in clinical malaria or low birth weight. CONCLUSIONS: ITNs used throughout pregnancy or from mid-pregnancy onwards have a beneficial impact on pregnancy outcome in malaria-endemic Africa in the first few pregnancies. The potential impact of ITNs in pregnant women and their newborns in malaria regions outside Africa requires further research

CD4 cell count and viral load monitoring in patients undergoing antiretroviral therapy in Uganda: cost effectiveness study

Objective To examine the cost and cost effectiveness of quarterly CD4 cell count and viral load monitoring among patients taking antiretroviral therapy (ART)

Utility of routine viral load, CD4 cell count, and clinical monitoring among adults with HIV receiving antiretroviral therapy in Uganda: randomised trial

Objective To evaluate the use of routine laboratory monitoring in terms of clinical outcomes among patients receiving antiretroviral therapy (ART) in Uganda

Does neighborhood environment influence girls' pubertal onset? findings from a cohort study

<p>Abstract</p> <p>Background</p> <p>Pubertal onset occurs earlier than in the past among U.S. girls. Early onset is associated with numerous deleterious outcomes across the life course, including overweight, breast cancer and cardiovascular health. Increases in childhood overweight have been implicated as a key reason for this secular trend. Scarce research, however, has examined how neighborhood environment may influence overweight and, in turn, pubertal timing. The current study prospectively examined associations between neighborhood environment and timing of pubertal onset in a multi-ethnic cohort of girls. Body mass index (BMI) was examined as a mediator of these associations.</p> <p>Methods</p> <p>Participants were 213 girls, 6-8 years old at baseline, in an on-going longitudinal study. The current report is based on 5 time points (baseline and 4 annual follow-up visits). Neighborhood environment, assessed at baseline, used direct observation. Tanner stage and anthropometry were assessed annually in clinic. Survival analysis was utilized to investigate the influence of neighborhood factors on breast and pubic hair onset, with BMI as a mediator. We also examined the modifying role of girls' ethnicity.</p> <p>Results</p> <p>When adjusting for income, one neighborhood factor (Recreation) predicted delayed onset of breast and pubic hair development, but only for African American girls. BMI did not mediate the association between Recreation and pubertal onset; however, these associations persisted when BMI was included in the models.</p> <p>Conclusions</p> <p>For African American girls, but not girls from other ethnic groups, neighborhood availability of recreational outlets was associated with onset of breast and pubic hair. Given the documented risk for early puberty among African American girls, these findings have important potential implications for public health interventions related to timing of puberty and related health outcomes in adolescence and adulthood.</p

The effect of Abstinence, Being faithful to one partner, and Condom use (ABC) messages on HIV infection among youth in Uganda

The effect of Abstinence, Being faithful to one partner, and Condom use (ABC) messages on HIV infection among youth in UgandaByJohn Paul EkwaruDoctor of Philosophy in EpidemiologyUniversity of California, BerkeleyProfessor Arthur Reingold, ChairUganda has suffered a devastating epidemic of HIV/AIDS for the last two and a half decades, with an estimated 2.6 million people becoming infected by 2005, half of whom had died by the end of that year. In 2009 an estimated 1.2 million people were living with HIV/AIDS in Uganda, including 120,000 who became infected in 2009. A campaign for abstinence from sex, being faithful to one sexual partner and condom use (ABC) became a pillar of HIV/AIDS prevention efforts in Uganda. Though there are indications that this intervention played a role in reducing the prevalence of HIV in Uganda, there are no data with which to estimate the impact of this intervention. It is important to determine the effect of this intervention, particularly among youth, who are thought to be a window of hope for changing the course of the HIV pandemic. There is also a need to explore the relationship between stigma and risky sexual behavior. While it has been shown that stigma affects uptake of voluntary counseling and testing (VCT), it is possible that stigma may also have effects on sexual behavior. While reluctance to take up VCT may be due to fear of being stigmatized when found to be HIV positive, it is also possible that fear of being stigmatized may lead to safer sexual behavior. Exploring the relationship between HIV/AIDS-related stigma and sexual behavior requires a valid measure of HIV/AIDS related stigma, but there is currently no such instrument that has been validated for use among youth in Uganda.The aims of this dissertation were to estimate the effects of the abstinence, being faithful, and condom use messages (ABC) on risky sexual behavior and HIV infection among youth in Uganda and to develop an instrument for measuring HIV/AIDS-related stigma among youth in Uganda.Chapter 1 presents an overview of HIV/AIDS and prevention efforts in Uganda.Chapter 2 utilizes data from the Uganda National HIV sero and behavioral Survey of 2004/2005 to estimate the effect of the ABC messages on the prevalence of HIV infection among youth in Uganda.Chapter 3 also utilizes data from the Uganda National HIV zero and behavioral Survey of 2004/2005 to estimate the effect of the ABC messages on risky sexual behavior among youth in Uganda.Chapter 4 presents a report on the development process for and psychometric properties of an instrument that was developed to measure HIV/AIDS-related stigma among youth in Uganda. Chapter 5 presents a summary of study findings, conclusions and implications for public health and future research

Insecticide-treated nets for preventing malaria in pregnancy

Background Malaria in pregnancy is associated with adverse consequences for mother and fetus. Protection with insecticide-treated nets (ITNs) during pregnancy is widely advocated, but evidence of their benefit has been inconsistent. Objectives To compare the impact of ITNs with no nets or untreated nets on preventing malaria in pregnancy. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register (February 2009), CENTRAL (The Cochrane Library 2009, Issue 1), MEDLINE (1966 to February 2009), EMBASE (1974 to February 2009), LILACS (1982 to February 2009), and reference lists. We also contacted researchers working in the field. Selection criteria Individual and cluster randomized controlled trials of ITNs in pregnant women. Data collection and analysis Three authors independently assessed the risk of bias in the trials and extracted data. Data were combined using the generic inverse variance method. Main results Six randomized controlled trials were identified, five of which met the inclusion criteria: four trials from sub-Saharan Africa compared ITNs with no nets, and one trial from Asia compared ITNs with untreated nets. Two trials randomized individual women and three trials randomized communities. In Africa, ITNs, compared with no nets, reduced placental malaria in all pregnancies (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.63 to 0.98). They also reduced low birthweight (RR 0.77, 95% CI 0.61 to 0.98) and fetal loss in the first to fourth pregnancy (RR 0.67, 95% CI 0.47 to 0.97), but not in women with more than four previous pregnancies. For anaemia and clinical malaria, results tended to favour ITNs, but the effects were not significant. In Thailand, one trial randomizing individuals to ITNs or untreated nets showed a significant reduction in anaemia and fetal loss in all pregnancies but not for clinical malaria or low birthweight. Authors' conclusions ITNs have a beneficial impact on pregnancy outcome in malaria-endemic regions of Africa when used by communities or by individual women. No further trials of ITNs in pregnancy are required in sub-Saharan Africa. Further evaluation of the potential impact of ITNs is required in areas with less intense and Plasmodium vivax transmission in Asia and Latin America

A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D

The Institute of Medicine (IOM) issues dietary recommendations on the request of the U.S. and Canadian governments. [...