Trends in bidi and cigarette smoking in India from 1998 to 2015, by age, gender and education.

OBJECTIVES: Smoking of cigarettes or bidis (small, locally manufactured smoked tobacco) in India has likely changed over the last decade. We sought to document trends in smoking prevalence among Indians aged 15-69 years between 1998 and 2015. DESIGN: Comparison of 3 nationally representative surveys representing 99% of India's population; the Special Fertility and Mortality Survey (1998), the Sample Registration System Baseline Survey (2004) and the Global Adult Tobacco Survey (2010). SETTING: India. PARTICIPANTS: About 14 million residents from 2.5 million homes, representative of India. MAIN OUTCOME MEASURES: Age-standardised smoking prevalence and projected absolute numbers of smokers in 2015. Trends were stratified by type of tobacco smoked, age, gender and education level. FINDINGS: The age-standardised prevalence of any smoking in men at ages 15-69 years fell from about 27% in 1998 to 24% in 2010, but rose at ages 15-29 years. During this period, cigarette smoking in men became about twofold more prevalent at ages 15-69 years and fourfold more prevalent at ages 15-29 years. By contrast, bidi smoking among men at ages 15-69 years fell modestly. The age-standardised prevalence of any smoking in women at these ages was 2.7% in 2010. The smoking prevalence in women born after 1960 was about half of the prevalence in women born before 1950. By contrast, the intergenerational changes in smoking prevalence in men were much smaller. The absolute numbers of men smoking any type of tobacco at ages 15-69 years rose by about 29 million or 36% in relative terms from 79 million in 1998 to 108 million in 2015. This represents an average increase of about 1.7 million male smokers every year. By 2015, there were roughly equal numbers of men smoking cigarettes or bidis. About 11 million women aged 15-69 smoked in 2015. Among illiterate men, the prevalence of smoking rose (most sharply for cigarettes) but fell modestly among men with grade 10 or more education. The ex-smoking prevalence in men at ages 45-59 years rose modestly but was low: only 5% nationally with about 4 current smokers for every former smoker. CONCLUSIONS: Despite modest decreases in smoking prevalence, the absolute numbers of male smokers aged 15-69 years has increased substantially over the last 15 years. Cigarettes are displacing bidi smoking, most notably among young adult men and illiterate men. Tobacco control policies need to adapt to these changes, most notably with higher taxation on tobacco products, so as to raise the currently low levels of adult smoking cessation.

Maternal vitamin D supplementation during pregnancy and lactation to promote infant growth in Dhaka, Bangladesh (MDIG trial): study protocol for a randomized controlled trial.

BACKGROUND: Vitamin D regulates bone mineral metabolism and skeletal development. Some observational studies have suggested that prenatal vitamin D deficiency increases the risk of adverse pregnancy and/or birth outcomes; however, there is scant evidence from controlled trials, leading the World Health Organization to advise against routine vitamin D supplementation in pregnancy. Importantly, little is known about the effect of maternal vitamin D status on infant linear growth in communities in South Asia where stunting is highly prevalent and maternal-infant vitamin D status is commonly suboptimal. METHODS/DESIGN: The Maternal Vitamin D for Infant Growth study is a randomized, placebo-controlled, dose-ranging trial of maternal vitamin D supplementation during pregnancy and lactation in Dhaka, Bangladesh. The primary aims are to estimate (1) the effect of maternal prenatal oral vitamin D3 supplementation (4200 IU/wk, 16,800 IU/wk, or 28,000 IU/wk, administered as weekly doses) versus placebo on infant length at 1 year of age and (2) the effect of maternal postpartum oral vitamin D3 supplementation (28,000 IU/wk) versus placebo on length at 1 year of age among infants born to women who received vitamin D 28,000 IU/wk during pregnancy. Generally healthy pregnant women (n = 1300) in the second trimester (17-24 weeks of gestation) are randomized to one of five parallel arms: placebo 4200 IU/wk, 16,800 IU/wk, or 28,000 IU/wk in the prenatal period and placebo in the postpartum period or 28,000 IU/wk in the prenatal period and 28,000 IU/wk in the postpartum period. Household- and clinic-based follow-up of mother-infant pairs is conducted weekly by trained personnel until 26 weeks postpartum and every 3 months thereafter. The primary trial outcome measure is length for age z-score at 1 year of age. Anthropometric measurements, clinical information, and biological specimens collected at scheduled intervals will enable the assessment of a range of maternal, perinatal, and infant outcomes. DISCUSSION: The role of vitamin D in maternal and infant health remains unresolved. This trial is expected to contribute unique insights into the effects of improving maternal-infant vitamin D status in a low-income setting where stunting and adverse perinatal outcomes represent significant public health burdens. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01924013. Registered on 13 August 2013.

Bioavailability of enteric-coated microencapsulated calcium during pregnancy: a randomized crossover trial in Bangladesh.

BACKGROUND: Prenatal calcium and iron supplements are recommended in settings of low dietary calcium intake and high prevalence of anemia. However, calcium administration may inhibit iron absorption. To overcome calcium-iron interactions, we developed a multi-micronutrient powder containing iron (60 mg), folic acid (400 µg), and calcium carbonate granules microencapsulated with a pH-sensitive enteric coating to delay intestinal release. OBJECTIVES: We aimed to establish in vivo evidence that enteric-coated (EC) calcium is bioavailable in pregnant women and to explore the dose-responsiveness of fractional calcium absorption (FCA) in pregnancy. DESIGN: This was a randomized crossover trial in pregnant women (26-28 wk of gestation) in Dhaka, Bangladesh. Participants were allocated to 1 of 3 dose groups (500, 1000, or 1500 mg elemental Ca). FCA was estimated in random order for EC and non-EC (control) granules by a dual-stable-isotope method ((44)Ca-labeled granules and intravenous (42)Ca) on the basis of the relative recovery of (44)Ca compared with (42)Ca in urine over 48 h. RESULTS: Forty-nine participants with FCA for both EC and non-EC granules were included in the primary analyses. FCA geometric means were as follows: 21.8% (500 mg), 9.2% (1000 mg), and 11.7% (1500 mg) for non-EC granules compared with 3.3% (500 mg), 1.2% (1000 mg), and 2.1% for EC granules. Cumulative 48-h FCA of EC calcium was 85% lower (P < 0.001) than that of non-EC calcium, after adjustment for dose. In comparison to 500 mg, the FCA for the 1000-mg dose was 61% lower (P < 0.001) and was 42% lower (P = 0.002) for the 1500-mg dose, after adjustment for formulation. CONCLUSIONS: A pH-sensitive enteric coating substantially reduced calcium absorption from a prenatal multi-micronutrient powder. In its current formulation, this novel supplement is not suitable for clinical use. FCA was highly dose-dependent, such that doses of 1000 and 1500 mg delivered only negligibly more bioavailable calcium than the 500-mg dose. This trial was registered at clinicaltrials.gov as NCT01678079.

Randomized placebo-controlled trial of high-dose prenatal third-trimester vitamin D3 supplementation in Bangladesh: the AViDD trial.

BACKGROUND: Antenatal vitamin D status may be associated with the risk of adverse pregnancy and neonatal outcomes; however, the benefits of vitamin D supplementation during pregnancy remain unknown. METHODS: We conducted a double-blind placebo-controlled randomized trial to evaluate the effect of high-dose prenatal 3rd trimester vitamin D3 supplementation on maternal and neonatal (cord blood) serum 25-hydroxyvitamin D (25(OH)D) concentration (primary biochemical efficacy outcome) and maternal serum calcium concentration (primary safety measure). Eligibility criteria were pregnant women aged 18 to <35 years, at 26 to 29 weeks gestation, and residing in Dhaka, Bangladesh. 160 women were randomized by 1:1 allocation to one of two parallel intervention groups; placebo (n = 80) or 35,000 IU/week of vitamin D3 (n = 80) until delivery. All participants, study personnel and study investigators were blind to treatment allocation. RESULTS: Mean maternal 25(OH)D concentration was similar in the vitamin D and placebo groups at baseline (45 vs. 44 nmol/L; p = 0.66), but was significantly higher in the vitamin D group vs. placebo group among mothers at delivery (134 vs. 38 nmol/L; p < 0.001) and newborns (cord blood: 103 vs. 39; p < 0.001). In the vitamin D group, 95% of neonates and 100% of mothers attained 25(OH)D >50 nmol/L, versus 21% mothers and 19% of neonates in the placebo group. No participants met criteria for hypercalcemia, there were no known supplement-related adverse events, and major pregnancy outcomes were similar between groups. CONCLUSIONS: Antenatal 3rd-trimester vitamin D3 supplementation (35,000 IU/week) significantly raised maternal and cord serum 25(OH)D concentrations above 50 nmol/L in almost all participants without inducing hypercalcemia or other observed safety concerns. Doses up to 35,000 IU/week may be cautiously used in further research aimed at establishing the clinical effects and safety of vitamin D3 supplementation in pregnancy. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov (NCT01126528).