Onset of acid-neutralizing action of a calcium/magnesium carbonate-based antacid using an artificial stomach model: an in vitro evaluation.

BACKGROUND: Calcium carbonate antacids are potent over-the-counter antacids, made more effective by adding magnesium carbonate (as in Rennie, Bayer). However, published studies on their onset of action are scarce. Therefore, we carried out an in vitro study comparing Rennie and placebo under simulated conditions of the human stomach (artificial stomach model) to reconfirm the onset of action of Rennie. METHODS: The validated Simulator of the Human Intestinal Microbial Ecosystem apparatus (SHIME, ProDigest, Belgium) was used, comprising five reactors simulating different parts of the human gastrointestinal tract. Both Rennie and placebo were dosed at two tablets per incubation over six independent, 2-h stomach incubations each. PRIMARY OBJECTIVES: to evaluate the time required to achieve pH 3.0, 3.5, 4.0 and 4.5, as well as the maximum pH reached. SECONDARY OBJECTIVE: to evaluate pepsin activity over the entire 2-h gastric incubation. RESULTS: After addition of Rennie, the gastric medium reached a pH of 3.0 within 40 s. The maximum pH of 5.24 was maintained for almost 10 min. In contrast, the maximum pH with placebo was 1.28 during the entire gastric simulation. Furthermore, Rennie strongly reduced the activity of mucosa-damaging pepsin during the period of increased pH. With placebo, the lower pH resulted in consistently high loads of digested peptides, reflecting the high cumulative and instantaneous pepsin activity. CONCLUSIONS: New data is a critical component in informed decision making. Our data confirm the high efficacy and fast onset of acid-neutralizing action of Rennie, which begins to work within seconds.

The Impact of Preconceptional Multiple-Micronutrient Supplementation on Female Fertility.

In industrialized countries, fertility has declined in recent years to the lowest recorded levels. Identifying modifiable factors that influence human fertility, such as diet, is therefore of major clinical and public health relevance. Micronutrient status is a modifiable risk factor that may have an impact on female fertility, as essential vitamins and minerals have important roles in the physiological processes that are involved. Adequate levels are important for oocyte quality, maturation, fertilization, and implantation, whereas antioxidants are vital to reduce oxidative stress, a process known to impair fertility. In women who are diagnosed as infertile, lower than recommended levels of certain micronutrients have been reported. A similar scenario has been found in a proportion of women of childbearing age in general, some of whom may be struggling to conceive. Supplementation studies with multiple micronutrients are still scarce, but the literature suggests that supplementation before conception can help restore micronutrient status to recommended levels and reduce oxidative stress when antioxidants are included. Overall, supplementation has a small but beneficial effect on fertility in healthy and infertile women, including a shorter time to pregnancy and an increased chance of becoming pregnant. Nevertheless, many studies are small or observational, and adequately powered randomized controlled trials of supplementation with multiple micronutrients are necessary to confirm any definite effects on fertility. This review substantiates the potential benefits of micronutrient supplementation beyond the prevention of neural tube defects, the traditionally viewed value of prenatal vitamin use.