Calcium is an essential element that plays numerous biological functions in the human body, of which one of the most important is skeleton mineralization. Bone is a mineralized connective tissue in which calcium represents the major component, conferring bone strength and structure. Proper dietary calcium intake is important for bone development and metabolism, and its requirement can vary throughout life. The mineral composition of drinking water is becoming relevant in the modulation of calcium homeostasis. In fact, calcium present in mineral drinking waters is an important quantitative source of calcium intake. This, together with its excellent bioavailability, contributes to the maintenance of the bone health. This article aims to examine studies that assessed the bioavailability of the calcium contained in calcium-rich mineral waters and their impact on bone health, including original data collected in a recent study in humans.

Water contributes significantly to health and a daily intake of 1.5 to 2 liters of water should be guaranteed, because a good hydration is essential to maintain the body water equilibrium, although needs may vary among people. However, worldwide population is far from the Recommended Allowance for water intake. Among the waters for human uses, there are 'waters (treated or not), intended for drinking, used for the food and beverages preparation or for other domestic purposes' and natural mineral waters, that are 'originated from an aquifer or underground reservoir, spring from one or more natural or bore sources and have specific hygienic features and, eventually, healthy properties'. According to the European Legislation (2009/54/EC Directive), physical and chemical characterization is used to make a classification of the different mineral waters, basing on the analysis of main parameters. Mineral composition enables to classify natural mineral waters as bicarbonate mineral waters, sulphate mineral waters, chloride mineral waters, calcic mineral waters, magnesiac mineral waters, fluorurate mineral waters, ferrous mineral waters and sodium-rich mineral waters. Although the concerns about bottled mineral waters (due to plasticizers and endocrine disruptors), many are the health effects of natural mineral waters and several studies explored their properties and their role in different physiological and pathological conditions.

Osteoporosis represent a widespread public health problem. The management and prevention of osteoporosis and related low energy fractures start with a correct lifestyle and proper nutrition. Several different nutrients are essential for bone and mineral metabolism, especially calcium. Nevertheless, a well-balanced nutrition, such as Mediterranean diet (MD), proved to be beneficial for several chronic diseases and also fragility fractures resulted lower in the Mediterranean area. A prospective observational study in a population of two hundred peri- and post-menopausal women (aged 30–80 years) was developed at Careggi hospital, Florence. Both MD adherence and dietary calcium intake were evaluated in occasion of a “first visit” and a “follow-up” visit, through validated questionnaires. From a descriptive point of view, although not statistically significant, in both visits a slight increase in calcium intake was observed for high adherence to MD diet. Moreover, a short nutritional interview (20 min) was applied in our population and demonstrated to be sufficient to significantly improve MD adherence level (mean score at T₀ = 6.98 ± 1.74 and T₁ = 7.53 ± 1.68), opening promising paths in osteoporosis prevention.

Metabolic bone disease (MBD) is a possible complication of intestinal failure (IF), with a multi-factorial pathogenesis. The reduction of bone density (BMD) may be radiologically evident before manifestation of clinical signs (bone pain, vertebral compression, and fractures). Diagnosis relies on dual-energy X-ray absorptiometry (DXA). Incidence and evolution of MBD are not homogeneously reported in children. The aim of this systematic review was to define the prevalence of MBD in IF children and to describe risk factors for its development. A comprehensive search of electronic bibliographic databases up to December 2021 was conducted. Randomized controlled trials; observational, cross-sectional, and retrospective studies; and case series published between 1970 and 2021 were included. Twenty observational studies (six case-control) were identified and mostly reported definitions of MBD based on DXA parameters. Although the prevalence and definition of MBD was largely heterogeneous, low BMD was found in up to 45% of IF children and correlated with age, growth failure, and specific IF etiologies. Data demonstrate that long-term follow-up with repeated DXA and calcium balance assessment is warranted in IF children even when PN dependence is resolved. Etiology and outcomes of MBD will be better defined by longitudinal prospective studies focused on prognosis and therapeutic perspectives.

Inflammatory bowel disease (IBDs), including Crohn’s disease (CD), and ulcerative colitis (UC) are complex diseases with a multifactorial etiology, associated with genetic, dietetic, and other environmental risk factors. Children with IBD are at increased risk for nutritional inadequacies, resulting from decreased oral intake, restrictive dietary patterns, malabsorption, enhanced nutrient loss, surgery, and medications. Follow-up of IBD children should routinely include evaluation of specific nutritional deficits and dietetic and/or supplementation strategies should be implemented in case deficiencies are detected. This narrative review focuses on the prevalence, risk factors, detection strategy, and management of micronutrient deficiencies in pediatric IBD.

Pregnancy is a delicate phase in woman's life that could become a risk factor for osteoporosis in pregnant women who do not meet recommended nutrient standards, especially for calcium and vitamin D. Mediterranean diet (MD) has been demonstrated to be beneficial for adequate nutrient intake. This article aims to evaluate the MD adherence and dietary calcium intake in a group of pregnant Italian women and to investigate how these are linked to each other and to fast glycemia at first trimester of pregnancy. Two hundred and seventy‐nine pregnant women were recruited at the gynecology units of two hospitals in Florence. Socio‐demographic, clinical information, and results of the first trimester blood sample analysis were collected. Two questionnaires, validated for evaluation of MD adherence and calcium intake, were administered to the pregnant women. Approximately 60% of the women had a high level of MD adherence, with a mean dietary calcium intake of 870.3 ± 335.3. In women with higher MD adherence level, fast glycemia resulted lower. Calcium intake was lower than Population Rate Intake for the Italian population (1,200 mg/daily) and was positively correlated to MD adherence score. The MD proved to be nutritious, as it was related to a higher calcium intake in this group of Italian women.