Vitamin D supplementation for women during pregnancy

ABSTRACT BACKGROUND: Vitamin D deficiency or insufficiency is thought to be common among pregnant women. Vitamin D supplementation during pregnancy has been suggested as an intervention to protect against adverse pregnancy outcomes. OBJECTIVES: To examine whether oral supplements with vitamin D alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve maternal and neonatal outcomes. METHODS: Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 February 2015), the International Clinical Trials Registry Platform (31 January 2015), the Networked Digital Library of Theses and Dissertations (28 January 2015) and also contacted relevant organisations (31 January 2015). Selection criteria: Randomized and quasi-randomized trials with randomization at either individual or cluster level, evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy. Data collection and analysis: Two review authors independently i) assessed the eligibility of studies against the inclusion criteria ii) extracted data from included studies, and iii) assessed the risk of bias of the included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach. MAIN RESULTS: In this updated review we included 15 trials assessing a total of 2833 women, excluded 27 trials, and 23 trials are still ongoing or unpublished. Nine trials compared the effects of vitamin D alone versus no supplementation or a placebo and six trials compared the effects of vitamin D and calcium with no supplementation. Risk of bias in the majority of trials was unclear and many studies were at high risk of bias for blinding and attrition rates. Vitamin D alone versus no supplementation or a placebo Data from seven trials involving 868 women consistently show that women who received vitamin D supplements alone, particularly on a daily basis, had higher 25-hydroxyvitamin D than those receiving no intervention or placebo, but this response was highly heterogeneous. Also, data from two trials involving 219 women suggest that women who received vitamin D supplements may have a lower risk of pre-eclampsia than those receiving no intervention or placebo (8.9% versus 15.5%; risk ratio (RR) 0.52; 95% CI 0.25 to 1.05, low quality). Data from two trials involving 219 women suggest a similar risk of gestational diabetes among those taking vitamin D supplements or no intervention/placebo (RR 0.43; 95% CI 0.05, 3.45, very low quality). There were no clear differences in adverse effects, with only one reported case of nephritic syndrome in the control group in one study (RR 0.17; 95% CI 0.01 to 4.06; one trial, 135 women, low quality). Given the scarcity of data for this outcome, no firm conclusions can be drawn. No other adverse effects were reported in any of the other studies. With respect to infant outcomes, data from three trials involving 477 women suggest that vitamin D supplementation during pregnancy reduces the risk preterm birth compared to no intervention or placebo (8.9% versus 15.5%; RR 0.36; 95% CI 0.14 to 0.93, moderate quality). Data from three trials involving 493 women also suggest that women who receive vitamin D supplements during pregnancy less frequently had a baby with a birthweight below 2500 g than those receiving no intervention or placebo (RR 0.40; 95% CI 0.24 to 0.67, moderate quality). In terms of other outcomes, there were no clear differences in caesarean section (RR 0.95; 95% CI 0.69 to 1.31; two trials; 312 women); stillbirths (RR 0.35 95% CI 0.06, 1.99; three trials, 540 women); or neonatal deaths (RR 0.27; 95% CI 0.04, 1.67; two trials, 282 women). There was some indication that vitamin D supplementation increases infant length (mean difference (MD) 0.70, 95% CI -0.02 to 1.43; four trials, 638 infants) and head circumference at birth (MD 0.43, 95% CI 0.03 to 0.83; four trials, 638 women). Vitamin D and calcium versus no supplementation or a placebo Women who received vitamin D with calcium had a lower risk of pre-eclampsia than those not receiving any intervention (RR 0.51; 95% CI 0.32 to 0.80; three trials; 1114 women, moderate quality), but also an increased risk of preterm birth (RR 1.57; 95% CI 1.02 to 2.43, three studies, 798 women, moderate quality). Maternal vitamin D concentration at term, gestational diabetes, adverse effects and low birthweight were not reported in any trial or reported only by one study. AUTHORS CONCLUSIONS: New studies have provided more evidence on the effects of supplementing pregnant women with vitamin D alone or with calcium on pregnancy outcomes. Supplementing pregnant women with vitamin D in a single or continued dose increases serum 25-hydroxyvitamin D at term and may reduce the risk of pre-eclampsia, low birthweight and preterm birth. However, when vitamin D and calcium are combined, the risk of preterm birth is increased. The clinical significance of the increased serum 25-hydroxyvitamin D concentrations is still unclear. In light of this, these results need to be interpreted with caution. Data on adverse effects were lacking in all studies. The evidence on whether vitamin D supplementation should be given as a part of routine antenatal care to all women to improve maternal and infant outcomes remains unclear. While there is some indication that vitamin D supplementation could reduce the risk of pre-eclampsia and increase length and head circumference at birth, further rigorous randomized trials are required to confirm these effects.

Consideraciones sobre la elaboración de las directrices de nutrición de la Organización Mundial de la Salud y su implementación / Considerations on the development of nutrition-related guidelines by the World Health Organization and their implementation

La Organización Mundial de la Salud (OMS) sigue un proceso complejo y riguroso para la elaboración de directrices mundiales. En el caso de las directrices relacionadas con nutrición, la participación conjunta de las autoridades de los Estados Miembros de la OMS y sus aliados, incluidos aquellos de la economía social y solidaria, es clave para fortalecer el proceso de elaboración de directrices informadas por las pruebas científicas y su posterior implementación, como parte de las estrategias nacionales de salud pública. Para las autoridades en materia de salud y desarrollo social, la OMS desarrolla una serie de herramientas para la formulación de políticas informadas por las pruebas científicas, considerando su pertinencia, relevancia e implementabilidad. Este proceso de adopción y adaptación debe considerar aspectos de equidad, para evitar la ampliación de brechas en salud. Las directrices mundiales de la OMS contribuyen a que las intervenciones en nutrición en sus Estados Miembros sean implementadas de manera adecuada. Dos experiencias de implementación de intervenciones en nutrición, una en Panamá y otra en Perú, ejemplifican este proceso. El artículo concluye sugiriendo profundizar en el conocimiento y aplicación de la investigación de la implementación de programas para identificar los factores que permiten a una intervención ser efectiva, tener una mejor estrategia de escalabilidad y contribuir a la equidad en salud.

The World Health Organization (WHO) follows a complex and rigorous process to develop global guidelines. With regard to nutrition-related guidelines, the joint participation of national authorities from Member States and their partners, including those of the social economy, is key to strengthening the process of evidence-informed guideline development and the subsequent implementation as part of national public health strategies. WHO puts forward a series of tools that can assist national authorities on health and social development in the elaboration of evidenceinformed policies, considering their pertinence, relevance and implementability. This adoption and adaptation process must consider equity in order to avoid widening existing inequities. WHO global nutrition guidelines contribute to the effective implementation of nutrition interventions in Member States. Two experiences of implementation, one in Panama and one in Peru, exemplify this process. The paper ends by suggesting a deeper understanding and utilization of implementation research during programmes to identify what factors ensure effective interventions, appropriate scale up strategies and greater health equity.

Metas globales de la organización mundial de la salud para mejorar la nutrición materna, del lactante y del niño pequeño / World Health Organization's global targets on maternal, infant and young child nutrition

La Asamblea Mundial de la Salud es el órgano decisorio supremo de la Organización Mundial de la Salud. Se reúne en Ginebra en Mayo de cada año con la asistencia de delegaciones de los Estados Miembros. La 65a Asamblea Mundial de la Salud realizada en Ginebra del 21 al 26 de Mayo de 2012, aprobó el Plan de Aplicación Integral sobre Nutrición de la Madre, el Lactante y el Niño Pequeño, el cual incluye seis metas globales fundamentales para lograr mejorías en relación con: el retraso en el crecimiento (talla baja para la edad) en niños, la anemia en mujeres en edad reproductiva, el bajo peso al nacer, el sobrepeso en niños, la lactancia materna exclusiva y la emaciación en menores de cinco años hasta el año 2025. Las metas globales fueron endosadas por los Países Miembros de la Organización Mundial de la Salud quienes se comprometieron a monitorear y hacer seguimiento del progreso hacia el alcance de las metas. Estas metas permiten identificar las áreas prioritarias de acción y propiciar cambios a nivel mundial. Este articulo describe cuáles son las metas globales y las herramientas disponibles para monitorear a nivel nacional los indicadores propuestos. Los resultados del instrumento de seguimiento desarrollado por la OMS se incorporarán en el informe mundial de nutrición que actualmente prepara un grupo independiente de expertos(AU)

The World Health Assembly is the supreme decision-making body of the World Health Organization. It meets every year in May in the city of Geneva and is attended by delegations of Member States. The 65th World Health Assembly held from the 21st to 26th of May 2012, approved the Comprehensive Implementation Plan on Maternal, Infant and Young Child Nutrition, which includes six key global targets to achieve improvements in: the stunting (low height for age) in children, anemia in women of reproductive age, low birth weight, overweight in children, exclusive breastfeeding, and wasting in children under five years by the year 2025. These goals were endorsed by the Member States of the World Health Organization who pledged to monitor and track the progress for achievements. The goals help to identify priority areas for action and foster global change. This article describes the six global goals and the tools that are available for adaptation at the national level and for monitoring progress indicators proposed by the Member States. The results of the monitoring tool developed by WHO will be incorporated in the world nutrition report which is being prepared by an independent group of experts(AU)

Valores de referencia de hierro, yodo, zinc, selenio, cobre, molibdeno, vitamina C, vitamina E, vitamina K, carotenoides y polifenoles para la población venezolana / Reference values of iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols for the Venezuelan population

Esta revisión de las recomendaciones de energía y nutrientes para la población Venezolana presenta los valores de hierro, yodo, zinc, selenio, cobre, molibdeno, vitamina C, vitamina E, vitamina K, carotenoides y polifenoles. Se adoptan definiciones internacionales de Ingestas Dietéticas de Referencia (DRIs por Dietary Reference Intakes) que incluyen: Ingesta Dietética Recomendada (RDA), Requerimiento Promedio Estimado (EAR), Ingesta Adecuada (AI) y Niveles de Ingesta Máximos Tolerables (UL). Las RDA para hierro: 11 mg/día para < 1 año, 7-10 mg/día niños, 8-11 mg/día para hombres, 8-18 mg/día para mujeres y 27 mg/día para embarazadas. RDA Yodo: 110-130 mg/ día recién nacidos, 90-120 mg/día niños y adolescentes y 150 mg/ día adultos, 220 mg/día embarazo y 290 mg/día lactancia. RDA Zinc: 2-3 mg/día < 1 año, 3-5 mg/día niños, 8-11 mg/día adolescentes y hombres, 8-9 mg/día adolescentes y mujeres, 12 mg/ día para embarazadas y 13 mg/día durante la lactancia. RDA Vitamina C: 40-50 mg/día recién nacidos, 15-45 mg/día niños, 75 mg/día adolescentes masculinos, 65 mg/día adolescentes femeninas, 90 mg/día hombres y 75 mg/día mujeres, 80-85 mg/día embarazadas y lactancia 115-120 mg/día. También se presentan valores de cobre, selenio, molibdeno, vitaminas E, K, carotenoides y polifenoles. Estas recomendaciones contribuirán al diseño de políticas adecuadas y eficientes que puedan ayudar a evitar o a tratar las consecuencias derivadas de la deficiencia o el exceso de estos nutrientes.

The review on iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols recommendations for Venezuela comprise the definitions adopted worldwide known as Dietary Reference Intakes (DRIs) that include Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL). The RDA for iron: 11 mg/day for infants < 1 year of age, 7 - 10 mg/day for children, 8-11 mg/day for males, 8-18 mg/day for females and 27 mg/day during pregnancy. RDA for iodine: 110-130 mg/day for infants, 90-120 mg/ day for children and adolescents, 150 mg/day for adults, 220 mg/ day for pregnancy and 290 mg/day during lactation. RDA Zinc: 2-3 mg/day for infants, 3-5 mg/day for children, 8-11 mg/day for male adolescents and adults, 8-9 mg/day for female adolescents and adults, 12 mg/day during pregnancy and 13 mg/day for lactation. RDA Vitamin C: 40-50 mg/day for infants, 15-45 mg/ day for children, 75 mg/day for male adolescents, 65 mg/day for female adolescents, 90 mg/day for adult males, 75 mg/day for adult females, 80-85 mg/day during pregnancy and 115-120 mg/ day during lactation. Recommendations for copper, selenium, molybdenum, vitamins E, K, carotenoids and polyphenols are also presented. These recommendations will help to design adequate and efficient policies that could help to avoid or to treat the consequences derived from the deficiency or the excess of these nutrients.

An evaluation of a global vitamin and mineral nutrition surveillance system / Evaluación de un sistema global de vigilancia nutricional sobre vitaminas y minerales

Evaluation at all levels is a fundamental function at World Health Organization (WHO). Evaluation of public health surveillance systems is essential to ensure that problems of public health importance are monitored efficiently and effectively. The WHO's Vitamin and Mineral Nutrition Information System (VMNIS) was evaluated from the perspective of public health surveillance and informatics. Steps included: engaging the stakeholders of the evaluation; describing the surveillance system; focusing the evaluation design; gathering credible evidence regarding system performance; justifying and stating conclusions and recommendations, and sharing lessons learned from the evaluation. Following this assessment, WHO has begun major efforts to upgrade and expand the VMNIS and now the database is more flexible and efficient. The database evaluation summarized in this paper provides a good example of how public health evaluation frameworks can lead to improved surveillance and enhanced information systems, thus making progress toward the ultimate goal of improving public health.

La evaluación en todos los niveles es una función fundamental en la Organización Mundial de la Salud (OMS). La evaluación de los sistemas de vigilancia epidemiológica es esencial para asegurar que los problemas de importancia para la salud pública sean monitorizados de manera eficiente y efectiva. El Sistema de Información Nutricional sobre Vitaminas y Minerales (VMNIS, por sus siglas en inglés) se evaluó desde la perspectiva de sistema de vigilancia e informática en salud pública. Los pasos incluyeron: el involucramiento de las partes interesadas en la evaluación, la descripción del sistema de vigilancia, el enfoque del diseño para la evaluación, la recopilación de pruebas fiables sobre el rendimiento del sistema, la justificación y desarrollo de conclusiones y recomendaciones, y la diseminación de las lecciones aprendidas de la evaluación. Después de este proceso, la OMS inició importantes esfuerzos para mejorar y ampliar el Sistema de Información Nutricional sobre Vitaminas y Minerales para lograr una base de datos más flexible y eficiente. Este artículo resume la evaluación de esta base de datos para documentar un buen ejemplo de cómo los marcos de evaluación en salud pública pueden llevar a mejorar la información en los sistemas de vigilancia contribuyendo de esta manera al objetivo final de mejorar la salud pública.

Wheat flour fortification for prevention and control of iron deficieny anemia in Latin America: issues to consider in a systematic evaluation

Iron deficiency continues to be a public health concern in many regions including Latin America. Various interventions such as routine supplementation with iron and folic acid to various target groups, fortification of staple foods such as wheat flour and corn meal, control of parasitic infections and improvement of sanitary conditions are implemented worldwide to address this micronutrient deficiency. Wheat flour fortification has been a common intervention to almost all countries in Latin America. Although this strategy has been underwav for several years, it seems critical to evaluate the program achievements in a systematic way in order to assess the intended and unintended outcomes and recommend actions for the future. The evaluation should include the assessment of dietary habits and the availability, access and consumption of new iron-fortified food products in the marketplace, and should consider the newer knowledge in food fortification science and technology. A systematic program evaluation can identify key issues affecting performance and provide recommendations that can be applied to improve program effectiveness. The CDC framework for evaluation of public health interventions can be used as a guide to lead the design and implementation of this task. A review of all the current and potential stakeholders involved is needed to renew and invigorate political commitment to food fortification as a strategy for iron deficiency prevention and control, in conjunction with other interventions. Reassessing the context of the fortification program, the country's food vehicle products market trends, understanding, possible changes in dietary habits and micronutrient consumption, and supplement usage could be done in order to better focus the program and provide useful recommendations to the stakeholders.

Salvado de trigo y cáncer de mama: revisitando la hipótesis del estrógeno / Wheat bran and breast cancer: revisiting the estrogen hypothesis

Breast cancer is the most relevant form of cancer among women in Latin America. Many studies have evaluated the hormonal mechanisms involved in mammary carcinogenesis, although new focus is aimed towards factors that can potentially be used individually to reduce risk. Wheat bran seems to show a consistent protective effect in mammary carcinogenesis. Wheat bran, besides high level of insoluble fiber, also contains phytic acid and lignins, phytochemicals that have shown to inhibit in vitro and in vivo growth of mammary cancer. The protective effect of wheat bran in breast carcinogenesis is greatest at the promotional phase and when supplemented to a high fat diet. Doses of wheat bran in the 9-12range have been consistently protective and the inconsistencies observed at higher doses may be dependent on the animal model used. This review examines the protective role of wheat bran in the development of breast cancer and the possible mechanisms involved.