Dietary calcium deficiency is considered to be widespread globally, with published estimates suggesting that approximately half of the world's population has inadequate access to dietary calcium. Calcium is essential for bone health, but inadequate intakes have also been linked to other health outcomes, including pregnancy complications, cancers, and cardiovascular disease. Populations in low‐ and middle‐income countries (LMICs) are at greatest risk of low calcium intakes, although many individuals in high‐income countries (HICs) also do not meet recommendations. Paradoxically, many LMICs with lower calcium intakes show lower rates of osteoporotic fracture as compared with HICs, though data are sparse. Calcium intake recommendations vary across agencies and may need to be customized based on other dietary factors, health‐related behaviors, or the risk of calcium‐related health outcomes. The lack of standard methods to assess the calcium status of an individual or population has challenged efforts to estimate the prevalence of calcium deficiency and the global burden of related adverse health consequences. This paper aims to consolidate available evidence related to the global prevalence of inadequate calcium intakes and associated health outcomes, with the goal of providing a foundation for developing policies and population‐level interventions to safely improve calcium intake and status where necessary.

Inadequate micronutrient intakes are relatively common in low‐ and middle‐income countries (LMICs), especially among pregnant women, who have increased micronutrient requirements. This can lead to an increase in adverse pregnancy and birth outcomes. This review presents the conclusions of a task force that set out to assess the prevalence of inadequate micronutrient intakes and adverse birth outcomes in LMICs; the data from trials comparing multiple micronutrient supplements (MMS) that contain iron and folic acid (IFA) with IFA supplements alone; the risks of reaching the upper intake levels with MMS; and the cost‐effectiveness of MMS compared with IFA. Recent meta‐analyses demonstrate that MMS can reduce the risks of preterm birth, low birth weight, and small for gestational age in comparison with IFA alone. An individual‐participant data meta‐analysis also revealed even greater benefits for anemic and underweight women and female infants. Importantly, there was no increased risk of harm for the pregnant women or their infants with MMS. These data suggest that countries with inadequate micronutrient intakes should consider supplementing pregnant women with MMS as a cost‐effective method to reduce the risk of adverse birth outcomes.

Calcium intake remains inadequate in many low‐ and middle‐income countries, especially in Africa and South Asia, where average intakes can be below 400 mg/day. Given the vital role of calcium in bone health, metabolism, and cell signaling, countries with low calcium intake may want to consider food‐based approaches to improve calcium consumption and bioavailability within their population. This is especially true for those with low calcium intake who would benefit the most, including pregnant women (by reducing the risk of preeclampsia) and children (by reducing calcium‐deficiency rickets). Specifically, some animal‐source foods that are naturally high in bioavailable calcium and plant foods that can contribute to calcium intake could be promoted either through policies or educational materials. Some food processing techniques can improve the calcium content in food or increase calcium bioavailability. Staple‐food fortification with calcium can also be a cost‐effective method to increase intake with minimal behavior change required. Lastly, biofortification is currently being investigated to improve calcium content, either through genetic screening and breeding of high‐calcium varieties or through the application of calcium‐rich fertilizers. These mechanisms can be used alone or in combination based on the local context to improve calcium intake within a population.

Most low‐ and middle‐income countries present suboptimal intakes of calcium during pregnancy and high rates of mortality due to maternal hypertensive disorders. Calcium supplementation during pregnancy is known to reduce the risk of these disorders and associated complications, including preeclampsia, maternal morbidity, and preterm birth, and is, therefore, a recommended intervention for pregnant women in populations with low dietary calcium intake (e.g., where ≥25% of individuals in the population have intakes less than 800 mg calcium/day). However, this intervention is not widely implemented in part due to cost and logistical issues related to the large dose and burdensome dosing schedule (three to four 500‐mg doses/day). WHO recommends 1.5–2 g/day but limited evidence suggests that less than 1 g/day may be sufficient and ongoing trials with low‐dose calcium supplementation (500 mg/day) may point a path toward simplifying supplementation regimens. Calcium carbonate is likely to be the most cost‐effective choice, and it is not necessary to counsel women to take calcium supplements separately from iron‐containing supplements. In populations at highest risk for preeclampsia, a combination of calcium supplementation and food‐based approaches, such as food fortification with calcium, may be required to improve calcium intakes before pregnancy and in early gestation.

The global population, including the United States, is experiencing a demographic shift with the proportion of older adults (aged ≥ 65 years) growing faster than any other age group. This demographic group is at higher risk for developing nutrition-related chronic conditions such as heart disease and diabetes as well as infections such as influenza and pneumonia. As a result, an emphasis on nutrition is instrumental for disease risk reduction. Unfortunately, inadequate nutrient status or deficiency, often termed hidden hunger, disproportionately affects older adults because of systematic healthcare, environmental, and biological challenges. This report summarizes the unique nutrition challenges facing the aging population and identifies strategies, interventions, and policies to address hidden hunger among the older adults, discussed at the scientific symposium “Hidden Hunger: Solutions for America’s Aging Population”, on March 23, 2018.

Thiamine deficiency has been typically associated with alcoholism or as a prevalent problem in low‐ and middle‐income countries (LMICs) whose populations rely on staple foods with a low content of thiamine. We conducted a literature review of published and unpublished data to identify relevant adult cases with confirmed thiamine deficiency of nonalcoholic cause in developed countries. We selected 17 reports with 81 adult cases of confirmed thiamine deficiency affecting adult patients with a wide range of ages and underlying conditions (e.g., cancer, gastrointestinal diseases, heart failure, and obesity). Thiamine deficiency may have been caused by disease‐related malnutrition, bariatric surgery, chronic use of diuretics, repeated vomiting, lack of thiamine in parenteral nutrition formulas, food insecurity, and reliance on monotonous or restrictive diets. Treatment with intravenous thiamine resulted in partial or complete recovery from the symptoms (cardiac, neurologic, and metabolic disorders) for most patients. The number and variety of symptomatic thiamine‐deficient adults identified in this review demonstrates that thiamine deficiency is not exclusive to LMICs and, in high‐income settings, is not exclusive to alcoholic patients. In developed countries, this serious but treatable condition can be expected in patients suffering from various medical conditions or following certain dietary patterns.