Janet King

Children's Hospital Oakland Research Institute | CHORI

In the 1970s, Doris Howes Calloway turned to the need to better understand mild to moderate malnutrition. She led the Nutrition Collaborative Research Support Program (NCRSP), which was designed to look at possible effects of inadequate food intakes on outcomes such as growth, morbidity, pregnancy, and childhood intellectual development. Although i...

This is the last in a series of 9 articles focusing on Doris Howes Calloway—A Woman Who Changed Nutrition Around the World. The pioneering “woman behind the science” is presented through the eyes of her students and associates. Her memorable humanitarian spirit, compassion, sensitivity, and the lens through which she viewed diversity, equity, and i...

Background: Agronomic zinc biofortification of wheat by foliar application increases wheat zinc content and total zinc absorption in humans. Objective: To assess the effect of agronomically biofortified whole wheat flour (BFW) on plasma zinc (PZC) compared to a fortified control wheat (PHFW) and unfortified control wheat (CW) when integrated in...

Throughout her career, Doris Howes Calloway sought to understand what influences human protein and energy requirements and metabolism in controlled and field settings. Much of her research became the basis for national and international dietary recommendations, many of which are in use today. She served on many committees of the US Food and Nutriti...

Zinc is an essential micronutrient, and its deficiency is perhaps the most prevalent and least understood worldwide. Recent advances have expanded the understanding of zinc’s unique chemistry and molecular roles in a vast array of critical functions. However, beyond the concept of zinc absorption, few studies have explored the molecular basis of zi...

During her career of over 40 years, Dr Doris Calloway held a variety of leadership/administrative positions while conducting groundbreaking research in human nutrition. In those positions, she illustrated the characteristics of dynamic, successful leaders. She led change in the nutritional sciences program at the University of California, Berkeley;...

Young children in resource-constrained settings are susceptible to zinc deficiency and its deleterious health effects. The objective of this secondary analysis was to evaluate the effects of the following six interventions on biomarkers of iron and zinc status among a subgroup of young children in Dhaka, Bangladesh, who participated in the Zinc in...

Dr Doris Howes Calloway had a keen interest in nutritionally vulnerable populations in North America and around the world. Given her scientific reputation and interests, she advised many national and international agencies on improving the health and well-being of populations at increased risk of malnutrition. In North America, she and her graduate...

Zinc, through its structural and cofactor roles, affects a broad range of critical physiological functions, including growth, metabolism, immune and neurological functions. Zinc deficiency is widespread among populations around the world, and it may, therefore, underlie much of the global burden of malnutrition. Current zinc fortification strategie...

When the US Department of Agriculture developed a new West Coast human nutrition research center in 1980, it turned to Dr Doris Calloway at the University of California at Berkeley, an internationally known and respected researcher in human nutrition, for expertise on controlled human nutrition metabolic research. This article highlights the import...

The U.S. Dietary Guidelines for Americans is an enormously influential policy that has guided US nutrition programs since 1980. During these last forty years, some researchers have expressed concern that the guidelines are based on an insufficiently rigorous assessment of the scientific evidence, a view that was largely substantiated by a Congressi...

Objectives: Stunting (length-for-age z score, LAZ < -2) has multiple causes and is prevalent in areas with low dietary zinc (Zn) intake. Zinc kinetics from non-stunted infants were used in a published model for predicting linear growth; here we directly measure zinc kinetics in stunted infants. Methods: Zinc kinetics were determined in 9-mo old...

The obesity pandemic continues unabated despite a persistent public health campaign to decrease energy intake (“eat less”) and increase energy expenditure (“move more”). One explanation for this failure is that the current approach, based on the notion of energy balance, has not been adequately embraced by the public. Another possibility is that th...

Food composition tables (FCTs) provide the levels of nutrients and other components in foods. Researchers, dietitians, educators, the food industry, and consumers use these tables to convert food intakes into nutrient intakes to evaluate foods, meals, and diets or to plan feeding programs. Doris Howes Calloway, along with her graduate students, mad...

Progress improving zinc nutrition globally is slowed by limited understanding of population zinc status. This challenge is compounded when small differences in measurement can bias the determination of zinc deficiency rates. Our objective was to evaluate zinc analytical accuracy and precision among different instrument types and sample matrices usi...

Although the importance of diet quality was identified more than 120 years ago, it was nearly 60 years before the specific quantitative nutrient needs for humans were determined. Dr Doris Howes Calloway, a nutrition professor at the University of California in Berkeley, established a metabolic unit for studying human nutrient requirements. This art...

At the beginning of her career after World War II, Doris Howes Calloway pushed forward into the rapidly expanding world of science and medicine and, for more than 50 years, focused her energies, abilities, and knowledge of foods, biochemistry, and physiology to advance the field of human nutrition as a science and to improve public health for all....

A sensitive and reliable biomarker of zinc status has yet to be identified, but observational research suggests that the exchangeable zinc pool (EZP) size may be a possible biomarker. This randomized, placebo-controlled trial aimed to compare the change in EZP size from baseline to endline in 174 children who were preventatively supplemented with 1...

A new variety of zinc biofortified wheat (Zincol-2016) was released in Pakistan in 2016. The primary aim of this study was to examine the effects of consuming Zincol-2016 wheat flour on biochemical and functional markers of zinc status in a population with widespread zinc deficiency. An individually-randomised, double-blind, placebo-controlled cros...

Background: Excessive gestational weight gain has been associated with increased total body fat (TBF), metabolic syndrome and abdominal obesity. However, little is known about the relationship of gestational weight gain with changes in metabolically active visceral or ectopic (hepatic and skeletal muscle) lipid stores. Objectives: In a prospecti...

Background Children in resource-limited settings remain vulnerable to zinc deficiency and its consequences. Objectives To evaluate the effects of different doses, durations, and frequencies of zinc supplementation on the incidence of diarrhea and change in linear growth among young children. Design We conducted a randomized, partially double-blin...

Background Rice biofortification with Zinc (Zn) can improve the Zn status of rice-consuming populations. However, the metabolic impact in humans consuming Zn biofortified rice is unknown. Objective To determine the effects of Zn biofortified rice on lipid metabolism in normolipidemic men. Design The men consumed a rice-based diet containing 6 mg...

Dr. Bruce Ames was a pioneer in understanding the role of oxidative stress and DNA damage, and in the 1990s began to make connections between micronutrient deficiencies and DNA damage. Zinc is an essential micronutrient for human health and a key component for the function of numerous cellular processes. In particular, zinc plays a critical role in...

Preventive zinc supplementation provided as a stand-alone dispersible tablet, or via home fortification as multiple micronutrient powders (MNPs), has been considered a potential strategy to prevent zinc deficiency and improve health (including immune) outcomes among children in low- and middle-income countries. However, the impact of zinc supplemen...

The decades-long dietary experiment embodied in the Dietary Guidelines for Americans (DGA) focused on limiting fat, especially saturated fat, and higher carbohydrate intake has coincided with rapidly escalating epidemics of obesity and type 2 diabetes (T2D) that are contributing to the progression of cardiovascular disease (CVD) and other diet-rela...

The last decade has seen nearly 20 papers reviewing the totality of the data on saturated fats and cardiovascular outcomes, which, altogether, have demonstrated a lack of rigorous evidence to support continued recommendations either to limit the consumption of saturated fatty acids or to replace them with polyunsaturated fatty acids. These papers w...

According to a commonly held view, the obesity pandemic is caused by overconsumption of modern, highly palatable, energy-dense processed foods, exacerbated by a sedentary lifestyle. However, obesity rates remain at historic highs, despite a persistent focus on eating less and moving more, as guided by the energy balance model (EBM). This public hea...

Background Zinc intake is associated with reduced risk of metabolic disease in adults, possibly due in part to zinc's role in essential fatty acid (EFA) desaturation. Although plasma zinc is the accepted indicator of zinc status, product-to-precursor activity indices of fatty acid desaturase (FADS) 1 and 2 have also been proposed as response indica...

Background Biofortification is a novel method for improving the nutritional value of grains. Wheat is widely consumed worldwide. Thus, wheat zinc biofortification may improve the zinc status of populations. Objectives We determined the effect of consuming zinc-biofortified wheat on plasma zinc concentrations and biomarkers of zinc-dependent functi...

Dietary bioactives are food substances that promote health but are not essential to prevent typical deficiency conditions. Examples include lutein and zeaxanthin, omega-3 fatty acids, and flavonoids. When quality evidence is available, quantified intake recommendations linking dietary bioactives with specific health benefits will enable health prof...

Background: The accurate estimation of zinc deficiency at the population level is important, as it guides the design, targeting, and evaluation of nutrition interventions. Plasma or serum zinc concentration (PZC) is recommended to estimate zinc nutritional status; however, concentrations may decrease in the presence of inflammation. Objectives:...

Plant-based staple diets common in low-income countries (LICs) often contain high levels of phytic acid (myo-inositol hexaphosphate, IP6), an inhibitor of zinc absorption. Depending on food source, handling and preparation, varying amounts of IP6 may be broken down to less phosphorylated inositol phosphates such as inositol tetra- and pentaphosphat...

Current research on diets and health focuses on composite food patterns and their likely impact on health outcomes. The Dietary Guidelines for Americans (DGA) have likewise adopted a more food group–based approach. By contrast, most nutrient profiling (NP) models continue to assess nutrient density of individual foods, based on a small number of in...

Almonds provide a satiating, healthy source of fat and fiber. The postprandial metabolic and satiety response to 2 ounces of nuts or dairy was assessed in 18 overweight/obese women during late pregnancy. Serum glucose, triglycerides, insulin, c-peptide, leptin, ghrelin, and lipoprotein particles were measured prior to and during a 5-h postprandial...

Phytate is widely distributed in the plant kingdom, and its significance for human nutrition has been often described. Data on phytate is available in very few composition tables, for a limited number of foods and mainly for raw products. With the aim of publishing the first global repository of analytical data on phytate, data on moisture, phytate...

Background Low calcium intake during pregnancy may cause maternal skeletal calcium mobilization to meet fetal needs. The Recommended Dietary Allowance (RDA) for calcium in nonpregnant, pregnant, or lactating women aged 19–50 y is 1000 mg/d; most women in the United States report consuming 60–80% of the calcium RDA. An insufficient calcium intake co...

Plant-based diets in low-income countries (LICs) have a high content of phytic acid (myo-inositol hexaphosphate [InsP6]) and associated magnesium, potassium, and calcium salts. Together, InsP6 acid and its salts are termed "phytate" and are potent inhibitors of iron and zinc absorption. Traditional food processing can reduce the InsP6 content throu...

Calories from any food have the potential to increase risk for obesity and cardiometabolic disease because all calories can directly contribute to positive energy balance and fat gain. However, various dietary components or patterns may promote obesity and cardiometabolic disease by additional mechanisms that are not mediated solely by caloric cont...

Objective To determine the effects of marginal zinc deficiency and repletion on essential fatty acid, sphingolipid, and lipoprotein metabolism. Methods Sixteen apparently healthy male subjects between ages of 18–45 were subjected to three sequential phases of dietary zinc intake modulation: Phase 1: Low Zinc intake: 6 mg/day with 1.5 g of phytate...

Objective To measure biomarkers of lipid metabolism in response to a marginal zinc depletion, repletion, and supplementation in healthy male subjects. Methods Eighteen male subjects between ages of 18–45 consumed a controlled diet (80% carbohydrate, 10% fat, 10% protein) with two levels of dietary zinc. Phase I: Low zinc: 6 mg/day with 1.5 mg of p...

Background: The size of the rapidly exchanging pool of body zinc has been suggested as having potential utility as a biomarker of zinc status. Knowledge of the relations of exchangeable zinc pool (EZP) size to relevant variables is necessary to adequately evaluate its use as a biomarker. Objective: We used regression analysis to investigate asso...

Objective: This analysis was focused on 1-year maternal and infant follow-up of a randomized trial that tested a weight management intervention conducted during pregnancy. Methods: One hundred fourteen women with obesity (mean BMI 36.7 kg/m(2) ) were randomly assigned at a mean of 15 weeks gestation to a weight management intervention or usual c...

Background: Large discrepancies exist among the dietary zinc recommendations set by expert groups. Objective: To describe the basis for the differences in the dietary zinc recommendations set by the World Health Organization, the US Institute of Medicine, the International Zinc Nutrition Consultative Group, and the European Food Safety Agency....

Population, human, animal, tissue, and molecular studies show collectively and consistently that maternal nutrition in the pre- or periconception period influences fetal growth and development, which subsequently affects the individual's long-term health. It is known that nutrition during pregnancy is an important determinant of the offspring's gro...

Longitudinal studies of calcium metabolism during pregnancy (PG) have shown that maternal calcium (Ca) absorption increases progressively from the first to the third trimester to meet the needs of the developing fetus. This increase in calcium absorption is directly related to maternal Ca intake. However, even with this increase in absorption, mate...

Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. Cellular, tissue, and whole-body zinc homeostasis is tightly controlled to sustain metabolic functions over a wide range of zinc intakes, making it difficult to assess zinc insufficiency or excess. The BOND (Biomarkers of Nutrition for Development) Zinc...

Background: Measurements of maternal fat mass (FM) are important for studies of maternal and fetal health. Common methods of estimating FM have not been previously compared in pregnancy with measurements using more complete body composition models. Objectives: The goal of this pilot study was to compare multiple methods that estimate FM, includi...

A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc tr...

What to eat during pregnancy has been a topic of interest for centuries. Initially, there were many philosophical beliefs about what pregnant women should eat to avoid "marking" their baby. Observations that poor women tended to have worse pregnancy outcomes than did women with adequate incomes showed that the quality of the mother's diet was linke...

Vitamin D deficiency is associated with adverse health outcomes, including impaired bone growth, gingival inflammation and increased risk for autoimmune disease, but the relationship between vitamin D deficiency rickets in childhood and long-term health has not been studied. In this study, we assessed the effect of early vitamin D deficiency on gro...

Background: Critically ill children have low plasma zinc (pZn), correlating with organ failure. Since Zn influences inflammation, immune function, and glucose control, Zn supplementation is a plausible therapeutic modality. We sought to determine a safe dose of intravenous (IV) Zn to restore pZn in critically ill children. Methods: Stepwise dose es...

Fortification is the process of adding nutrients or non-nutrient bioactive components to edible products (e.g., food, food constituents, or supplements). Fortification can be used to correct or prevent widespread nutrient intake shortfalls and associated deficiencies, to balance the total nutrient profile of a diet, to restore nutrients lost in pro...

Across many cultures in the United States, potatoes are an almost-universally popular vegetable and are good sources of several shortfall nutrients, such as potassium, magnesium, fiber, and vitamin C. In current US dietary guidance and nutrition policy, white potatoes are, at best, taken for granted, or at worst, excluded. Potatoes may contribute t...

Maternal nutritional status is an important predictor of infant birthweight. Most previous attempts to improve birthweight through multiple micronutrient supplementation have been initiated after women are pregnant. Interventions to improve maternal nutritional status prior to conception may be more effective in preventing low birthweight and impro...

Objective Observational studies suggest that minimal gestational weight gain (GWG) may optimize pregnancy outcomes for obese women. This trial tested the efficacy of a group-based weight management intervention for limiting GWG among obese women.Methods One hundred and fourteen obese women (BMI [mean ± SD] 36.7 ± 4.9 kg/m2) were randomized between...

Since 1980, when inaugural national dietary guidance was to “avoid too much sodium,” recommendations have evolved to the 2010 Dietary Guidelines for Americans’ quantified guidance of 2300 and 1500 mg/d [USDA and U.S. Department of Health and Human Services. Dietary guidelines for Americans, 1st (http://www.cnpp.usda.gov/DGAs1980Guidelines.htm) and...

Plasma zinc concentration (PZC) is a recommended biomarker to assess zinc status and the risk of zinc deficiency in populations. However, the relation between PZC and clinical signs of zinc deficiency remains uncertain. These analyses were conducted to evaluate the relation between PZC and clinical signs of zinc deficiency and to determine a cutoff...

Both fresh and processed foods make up vital parts of the food supply. Processed food contributes to both food security (ensuring that sufficient food is available) and nutrition security (ensuring that food quality meets human nutrient needs). This ASN scientific statement focuses on one aspect of processed foods: their nutritional impacts. Specif...

Low calcium intakes during pregnancy may mobilize the maternal skeletal calcium to meet fetal needs. The objective of this study was to determine the effect of maternal calcium supplementation on peripheral cortical and trabecular bone loss during pregnancy (PG) and gain postpartum (PP). Sixty‐four women (21 African American, 20 Caucasian, 10 Hispa...

Zinc deficiency continues to be a major concern of international nutrition, yet there are still few sensitive and reliable biomarkers for identifying moderate zinc deficiency or monitoring changes in zinc status. Plasma zinc content is used most frequently, but it is influenced by conditions other than zinc intake and, therefore, is not reliable ex...

The extra energy required for synthesis and maintenance of new tissue increases the REE during pregnancy. The net change may vary 8‐fold with higher increases seen in obese than non‐obese women. Our objective was to identify body composition and hormonal factors influencing the REE of obese women during the last half of pregnancy. A total of 64 wom...

The global epidemic of zinc deficiency is likely contributing to the development of chronic disorders such as cancer, insulin resistance, and immune dysfunction, though reliable biomarkers for human zinc deficiency are not currently available. To discover novel indicators of zinc deficiency in humans, untargeted metabolomic and lipidomic profiles w...

Plasma zinc concentration (PZC) is a recommended biomarker to assess zinc (Zn) status and the risk of Zn deficiency in populations. However, the relationship between PZC and clinical signs of Zn deficiency remains uncertain. Thus, we analyzed available data from dietary Zn restriction studies and case reports of acrodermatitis enteropathica (AE) to...

Patients with thalassemia major (Thal) frequently have low plasma zinc, which has been associated with low bone mass. The objective was to determine the effect of zinc supplementation on bone mass in patients with Thal. Forty-two subjects (21 females aged 10-30 y) with Thal and low bone mass were randomly assigned to receive 25 mg Zn/d or placebo....

Background / Purpose: Patients with thalassemia major (Thal) frequently have low plasma zinc which has been associated with low bone mass. The goal of this study was to determine the effect of zinc supplementation on bone mass in young patients with thalassemia. Main conclusion: Using intention to treat analysis, and linear models for longitud...

The white potato is a concentrated source of carbohydrate, dietary fiber, and resistant starch and continues to be the staple food of choice for many cultures. The white potato is also a concentrated source of vitamin C and potassium. Two of the nutrients in white potatoes, dietary fiber and potassium, have been designated as nutrients of concern i...

Zinc deficiency has an estimated prevalence of 31% globally, and can lead to poor pregnancy outcomes, immune dysfunction, and increased risk for chronic disorders. A barrier to elucidating the exact role of zinc in human health is a lack of reliable clinical biomarkers for zinc status in humans. Currently used plasma zinc levels, lack both sensitiv...

Drinking water appears to accelerate weight loss in adults consuming hypocaloric diets when the volume of water is over 1L/d or associated with decreases in urine osmolality. This study explored whether drinking water to dilute urine similarly accelerates weight loss in pre‐adolescents, and if the effect is mediated by cell hydration effects on ins...