More than half of the world’s population consumes inadequate levels of micronutrients essential for health, including calcium, iron, and vitamins C and E, according to a new study by researchers at the Harvard TH Chan School of Public Health, UC Santa Barbara (UCSB) and Global Alliance for Improved Nutrition (GAIN).
This is the first study to provide global estimates of inadequate intake of 15 micronutrients essential to human health.
Micronutrient deficiencies are one of the most common forms of malnutrition worldwide, and each deficiency has its own health consequences, from poor pregnancy outcomes to blindness and increased susceptibility to infectious diseases.
Previous research has estimated and consumed by humans; this study assesses whether these intakes meet the recommended requirements for human health and looks at the deficiencies that men and women specifically face throughout their lives.
Essential micronutrients for human health
“The study is a big step forward,” said co-lead author Chris Free, a research professor at UCSB. “Not only because it is the first to estimate 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 researchers used data from the Global Dietary Database, the World Bank and other surveys in 31 countries to compare nutritional requirements with nutritional intake among the population of 185 countries.
They divided the populations into men and women belonging to 17 age groups: from zero to 80 years in five-year periods, as well as an 80+ group. The evaluation looked at 15 vitamins and minerals: calcium, iodine, iron, riboflavin, folate, zinc, magnesium, selenium, thiamin, niacin, and vitamins A, B6, B12, C, and E.
The study found significant insufficient intake for nearly , ruling out fortification as a potential source of additional nutrients.
Insufficient intake for almost all micronutrients assessed
Insufficient intake was particularly prevalent for iodine (68% of the global population), vitamin E (67%), calcium (66%) and iron (65%).
More than half of people consumed inadequate levels of riboflavin, folate and vitamins C and B6. Niacin intake was closest to adequate, with 22% of the global population consuming inadequate levels, followed by thiamin (30%) and selenium (37%).
Estimated inadequate intake was higher in women than men for iodine, vitamin B12, iron and selenium within the same country and age group. In contrast, compared to women, more men consumed inadequate levels of calcium, niacin, thiamin, zinc, magnesium, and vitamins A, C, and B6, he writes.
While patterns of micronutrient inadequacy emerged more clearly by gender, the researchers also noted that men and women between the ages of 10 and 30 were most likely to have low levels of calcium intake, particularly in South and East Asia and Sub-Saharan Africa. Calcium intake was also low in North America, Europe and Central Asia.
