Harvard-GAIN study: worrying nutritional deficiencies worldwide
More than half of the world’s population has nutritional deficiencies. That is the worrying result of a recent study published in The Lancet Global Health by researchers from the Harvard T.H. Chan School of Public Health, UC Santa Barbara (UCSB) and the Global Alliance for Improved Nutrition (GAIN). The authors analysed the intake of 15 micronutrients, including iron, iodine, calcium and vitamins, for different age groups and sexes. According to the study, using a modelling approach based on dietary data from 185 countries, more than 5 billion people do not get enough essential vitamins and minerals such as iron, riboflavin, folate, calcium, iodine, and vitamins C and E.
The inadequate intake of essential micronutrients is one of the most common forms of malnutrition globally, affecting people in all regions and income groups and has alarming health consequences, such as adverse pregnancy outcomes, increased susceptibility to infectious diseases and blindness. The study also shows gender differences in micronutrient intake, with women tending to consume less iodine, vitamin B12, iron and selenium. In contrast, men consume less niacin, thiamin, zinc, magnesium and vitamins A, C and B6. This study is significant and alarming since it provides detailed global estimates of micronutrient deficiencies based on dietary intake. It highlights serious deficits in different regions and population groups and suggests the need for targeted nutritional interventions.
It is the first study to provide global estimates of inadequate consumption of micronutrients critical to human health. Previous research has estimated the micronutrients available to and consumed by people. In contrast, this study evaluates whether these intakes meet the requirements recommended for human health and looks at the inadequacies specifically facing males and females across their lifespans. The results provide a roadmap for action by showing which population groups are at risk of deficiency for specific nutrients.
Co-lead author Chris Free, a research professor at UCSB, is reported to have said: “Our study is a big step forward. Not only because it is the first to estimate inadequate micronutrient intakes for 34 age-sex groups in nearly every country, but also because it makes these methods and results easily accessible to researchers and practitioners”. The study showed that inadequate intake was especially prevalent for iodine (68% of the global population), vitamin E (67%), calcium (66%), and iron (65%). Intake of niacin was closest to sufficient, with 22% of the global population consuming inadequate levels, followed by thiamin (30%) and selenium (37%).
A senior technical specialist at GAIN, Ty Beal, is reported to have said: “These results are alarming. Most people—even more than previously thought, across all regions and countries of all incomes—are not consuming enough of multiple essential micronutrients. These gaps compromise health outcomes and limit human potential on a global scale.”
Dietary recommendations focused on addressing environmental challenges, such as further reductions in nutrient-dense foods, such as meat and animal-based foods, can only worsen matters. We hope these findings will lead to new and wiser recommendations that consider not only the environment but also human health.