Billions of People Have Inadequate Micronutrients, Study Estimates

Many diseases worldwide are caused by vitamin and mineral deficiencies.

Selection of "healthy" foods: fruits, seeds, cereals, and vegetables.

More than half the world’s population is deficient in micronutrients such as vitamins and minerals, according to a new study.

According to the study, published in Lancet Global Health, 99.3 percent of the global population is missing at least one important micronutrient.

The researchers collected data from 31 countries, which they used to estimate micronutrient consumption across 185 nations.

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“Our study is a big step forward,” Chris Free, research professor at the University of California–Santa Barbara and co-lead author, said. “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.”

Deficiencies in micronutrients harm health and can lead to a range of preventable health conditions, the researchers say.

“Iron deficiency is the most common cause of anaemia, leading to impaired cognition and adverse pregnancy outcomes. Vitamin A deficiency is the leading cause of preventable blindness globally, affecting mostly children and pregnant women,” the authors wrote.

“These results are alarming,” Ty Beal, lead author, said in a press release. “These gaps compromise health outcomes and limit human potential on a global scale.”

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The researchers said the new study is the first to provide global estimates of inadequate consumption of 15 micronutrients critical to human health.

“These results can be used by public health practitioners to target populations in need of intervention,” the researchers said.

7 Common Deficiencies

The researchers identified seven common micronutrients that people are deficient in, namely iodine, vitamin E, calcium, iron, riboflavin (vitamin B2), folate, and vitamin C. In the United States, vitamin E, iodine, and vitamin C top the list.

More than half of the world’s children under 5 are deficient in vitamin A, iron, or zinc.

Each micronutrient deficiency has unique consequences, with multiple deficiencies potentially lowering quality of life and lifespan. The study revealed several global deficiency rates and highlighted the effects:

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Iodine (68 percent): Vital for cognitive development in infants. Iodine plays an essential role for pregnant and breastfeeding women. Common sources of iodine are iodized salt, seaweed, and seafood.

Vitamin E (67 percent): Deficiency can cause muscle weakness and impaired coordination. Nuts, seeds, and vegetable oils are common sources of vitamin E.

Calcium (66 percent): Deficiencies can cause weak and brittle bones. Dairy and fish are common sources of calcium.

Iron (65 percent): Deficiencies can cause anemia, affecting cognition and pregnancy outcomes. Red meat and eggs are common sources of iron.

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Riboflavin (55 percent): Deficiencies can cause non-specific symptoms like eye sensitivity and neurological symptoms like seizures and migraines. Eggs, meat, and dairy are main sources of riboflavin.

Folate (54 percent): Folate is needed early in pregnancy to reduce the risk of stillbirths and severe birth defects of the brain and spinal cord. Nuts and leafy greens are main sources of folate.

Vitamin C (53 percent): Deficiencies can cause gum bleeding and poor wound healing. Peppers, tomatoes, and citrus fruits are common sources of vitamin C.

Other less common deficiencies include inadequate vitamin A and zinc. Vitamin A deficiencies can cause blindness and zinc helps prevent infectious disease.

The researchers found that females consistently showed higher deficiency rates for iodine, iron, and the mineral selenium.  Males, however, were more deficient in magnesium, vitamin B6, zinc, vitamin C, vitamin A, thiamin (vitamin B1), and niacin (vitamin B3).