Effects of maternal calcium supplementation on offspring blood pressure and growth in childhood and adolescence in a population with a low-calcium intake: follow-up study of a randomized controlled trial.

Background: The World Health Organization recommends calcium supplementation (1500-2000 mg/d) during pregnancy for women with a low-calcium intake.

Objectives: The purpose of this study was to investigate whether pregnancy calcium supplementation affects offspring blood pressure and growth in The Gambia where calcium intakes are low (300-400 mg/d).

Methods: Follow-up of offspring born during a randomized controlled trial of pregnancy calcium supplementation (ISRCTN96502494, 1996-2000) in which mothers were randomly assigned to 1500 mg Ca/d (Ca) or placebo (P) from 20 wk pregnancy to delivery.

Changes in Bone Mineral Density During and After Lactation in Ugandan Women With HIV on Tenofovir-Based Antiretroviral Therapy.

Antiretroviral therapy (ART) in people living with human immunodeficiency virus (HIV) is associated with bone loss, but data are limited in lactation, when physiological bone mineral mobilization is occurring. This research charted changes in areal bone mineral density (aBMD) during and after lactation in Ugandan women with HIV (WWH) initiated onto ART in pregnancy, compared to women without HIV (REF). One-hundred WWH on tenofovir-based ART and 100 REF were enrolled in pregnancy.

Aetiology of nutritional rickets in rural Bangladeshi children.

Objectives: A high prevalence of rickets of unknown aetiology has been reported in Chakaria, Bangladesh. Classically, rickets is caused by vitamin D deficiency but increasing evidence from Africa and Asia points towards other nutritional deficiencies or excessive exposure to some metals. The aim of this study was to investigate the aetiology of rickets in rural Bangladeshi children.

Sequences of Regressions Distinguish Nonmechanical from Mechanical Associations between Metabolic Factors, Body Composition, and Bone in Healthy Postmenopausal Women.

Background: There is increasing recognition of complex interrelations between the endocrine functions of bone and fat tissues or organs.

Objective: The objective was to describe nonmechanical and mechanical links between metabolic factors, body composition, and bone with the use of graphical Markov models.

Methods: Seventy postmenopausal women with a mean ± SD age of 62.

Vitamin D supplementation in older people (VDOP): Study protocol for a randomised controlled intervention trial with monthly oral dosing with 12,000 IU, 24,000 IU or 48,000 IU of vitamin D₃.

Unlabelled: The randomised, double blind intervention trial 'Optimising Vitamin D Status in Older People' (VDOP) will test the effect of three oral dosages of vitamin D given for one year on bone mineral density (BMD) and biochemical markers of vitamin D metabolism, bone turnover and safety in older people. VDOP is funded by Arthritis Research UK, supported through Newcastle University and MRC Human Nutrition Research and sponsored by the Newcastle upon Tyne Hospitals NHS Foundation Trust.a

Background: Vitamin D insufficiency is common in older people and may lead to secondary hyperparathyroidism, bone loss, impairment of muscle function and increased risk of falls and fractures.

Randomized, placebo-controlled, calcium supplementation trial in pregnant Gambian women accustomed to a low calcium intake: effects on maternal blood pressure and infant growth.

Background: Dietary calcium intake in rural Gambian women is very low (∼350 mg/d) compared with international recommendations. Studies have suggested that calcium supplementation of women receiving low-calcium diets significantly reduces risk of pregnancy hypertension.

Objective: We tested the effects on blood pressure (BP) of calcium carbonate supplementation (1500 mg Ca/d) in pregnant, rural Gambian women.

Unexpected long-term effects of calcium supplementation in pregnancy on maternal bone outcomes in women with a low calcium intake: a follow-up study.

Background: Calcium supplementation of pregnant Gambian women with a low calcium intake results in lower maternal bone mineral content in the subsequent lactation.

Objective: The objective was to investigate whether the lower bone mineral content persists long term.

Design: All women in the calcium supplementation trial (International Trial Registry ISRCTN96502494) who had been scanned with dual-energy X-ray absorptiometry at 52 wk of lactation (L52; n = 79) were invited for follow-up when neither pregnant nor lactating for ≥3 mo (NPNL) or at 52 wk postpartum in a future lactation (F52).

Dietary intake and body composition in HIV-positive and -negative South African women.

Objective: The present paper examines dietary intake and body composition in antiretroviral (ARV)-naïve HIV-positive compared with HIV-negative South African women, as well as the impact of disease severity on these variables.

Design: Baseline data from a longitudinal study assessing bone health in HIV-negative and HIV-positive premenopausal South African women over 18 years of age were used. Anthropometry and body composition, measured by dual energy X-ray absorptiometry, were analysed together with dietary intake data assessed using an interviewer-based quantitative FFQ.

Critical windows for nutritional interventions against stunting.

An analysis of early growth patterns in children from 54 resource-poor countries in Africa and Southeast Asia shows a rapid falloff in the height-for-age z score during the first 2 y of life and no recovery until ≥5 y of age. This finding has focused attention on the period -9 to 24 mo as a window of opportunity for interventions against stunting and has garnered considerable political backing for investment targeted at the first 1000 d. These important initiatives should not be undermined, but the objective of this study was to counteract the growing impression that interventions outside of this period cannot be effective.

Calcium economy in human pregnancy and lactation.

Pregnancy and lactation are times of additional demand for Ca. Ca is transferred across the placenta for fetal skeletal mineralisation, and supplied to the mammary gland for secretion into breast milk. In theory, these additional maternal requirements could be met through mobilisation of Ca from the skeleton, increased intestinal Ca absorption efficiency, enhanced renal Ca retention or greater dietary Ca intake.

Iron status and fibroblast growth factor-23 in Gambian children.

A relationship between iron and fibroblast growth factor-23 (FGF23) metabolic pathways has been proposed. Iron deficiency anaemia is prevalent in The Gambia and concentrations of fibroblast growth factor-23 FGF23 are elevated in a large percentage of Gambian children with rickets-like bone deformity. We speculate that low iron status may be involved in the aetiology of Gambian rickets.

Follow-up study of Gambian children with rickets-like bone deformities and elevated plasma FGF23: possible aetiological factors.

We have previously reported on a case-series of children (n=46) with suspected calcium-deficiency rickets who presented in The Gambia with rickets-like bone deformities. Biochemical analyses discounted vitamin D-deficiency as an aetiological factor but indicated a perturbation of Ca-P metabolism involving low plasma phosphate and high circulating fibroblast growth factor-23 (FGF23) concentrations. A follow-up study was conducted 5 years after presentation to investigate possible associated factors and characterise recovery.

Nutritional supplementation during pregnancy and offspring cardiovascular disease risk in The Gambia.

Background: Maternal nutritional intake during pregnancy may have important consequences for long-term health in offspring.

Objective: The objective was to follow up the offspring in 2 randomized trials of nutrient supplementation during pregnancy to investigate the effect on cardiovascular disease (CVD) risk in offspring.

Design: We recruited offspring born during 2 trials in The Gambia, West Africa.

Effect of maternal calcium supplementation on offspring blood pressure in 5- to 10-y-old rural Gambian children.

Background: Evidence suggests that increased maternal calcium intake during pregnancy may result in lower offspring blood pressure, prompting calls for more robust data in this field, particularly in settings of habitually low calcium intake.

Objective: The objective was to investigate the effect of maternal calcium supplementation on blood pressure in offspring by recruiting children born after a randomized, double-blind, placebo-controlled trial of calcium supplementation during pregnancy.

Design: Children (n = 389) from a rural area of The Gambia (mean age: 7.

Effect of calcium supplementation in pregnancy on maternal bone outcomes in women with a low calcium intake.

Background: Mobilization of maternal bone mineral partly supplies calcium for fetal and neonatal bone growth and development.

Objective: We investigated whether pregnant women with low calcium intakes may have a more extensive skeletal response postpartum that may compromise their short- or long-term bone health.

Design: In a subset of participants (n = 125) in a double-blind, randomized, placebo-controlled trial (International Trial Registry: ISRCTN96502494) in pregnant women in The Gambia, West Africa, with low calcium intakes (approximately 350 mg Ca/d), we measured bone mineral status of the whole body, lumbar spine, and hip by using dual-energy X-ray absorptiometry and measured bone mineral status of the forearm by using single-photon absorptiometry at 2, 13, and 52 wk lactation.

Evidence for a downward secular trend in age of menarche in a rural Gambian population.

Menarcheal age is a key indicator of female maturity and development. Studies in many countries have reported a downward secular trend in age of menarche over the past century. This study presents data gained using the 'status quo' method and interval regression to estimate median menarcheal age of girls in a rural Gambian community.

Ethnic differences in parathyroid hormone secretion and mineral metabolism in response to oral phosphate administration.

Ethnic differences in bone metabolism have been reported and it has been suggested that these may be partly due to prolonged exposure to an elevated plasma parathyroid hormone (PTH) concentration or a decreased sensitivity to PTH. We explored ethnic differences in bone and mineral metabolism by 5 days of oral phosphate (P) loading to stimulate PTH secretion. Healthy older people from UK (B), The Gambia (G) and China (C), 15 individuals from each sex and ethnic group, were studied.

Vitamin D Deficiency and Its Health Consequences in Africa.

Africa is heterogeneous in latitude, geography, climate, food availability, religious and cultural practices, and skin pigmentation. It is expected, therefore, that prevalence of vitamin D deficiency varies widely, in line with influences on skin exposure to UVB sunshine. Furthermore, low calcium intakes and heavy burden of infectious disease common in many countries may increase vitamin D utilization and turnover.

Changes in bone mineral status and bone size during pregnancy and the influences of body weight and calcium intake.

Background: Calcium may be mobilized from the maternal skeleton during pregnancy, which may be influenced by several factors.

Objective: The objective was to investigate changes in bone mineral status and size during pregnancy and to consider the influences of body weight and calcium intake.

Design: Thirty-four British women were studied before pregnancy and 2 wk postpartum (Preg).

Vitamin D across the lifecycle: physiology and biomarkers.

The field of vitamin D public health research has a pressing need to define sensitive and specific predictors of vitamin D status that can be used to determine whether an individual or population has a supply of vitamin D that is sufficient to meet requirements. The aim of this review is to highlight the considerations needed when evaluating evidence of the relations between vitamin D biomarkers and functional or health outcomes across the life cycle. It draws attention to the importance of distinguishing between biomarkers of supply, function, and outcome and of considering the many factors that could influence interpretation, such as life stage, ethnicity, body mass index, liver and kidney function, and dietary calcium and phosphorus intake.

Efficiency of autoregulatory homeostatic responses to imposed caloric excess in lean men.

Obesity implies a failure of autoregulatory homeostatic responses to caloric excess. We studied the mechanisms, effectiveness, and limits of such responses in six lean (21.9 +/- 1.

Nutrition and bone growth and development.

The growth and development of the human skeleton requires an adequate supply of many different nutritional factors. Classical nutrient deficiencies are associated with stunting (e.g.