Micronutrients are defined as nutrients that are essential for health and survival in trace amounts.
Micronutrients are essential nutrients, including vitamins and minerals, that the body requires in small amounts to support various physiological functions and maintain health.
There are approximately 20 essential micronutrients and a deficiency in one or more as metabolic, proteome, and genomic effects.
Micronutrients are categorized as water, soluble and fat soluble, vitamins, and trace minerals, meaning that they are required in an amount of less than 100 mg per day.
The recommended nutrient intake of vitamins and minerals have been determined for each of the approximately 22 population groups based on age, sex, pregnancy, and lactation status.
There are over 2 billion people worldwide who have a variety of micronutrient deficiencies.
The RDA is used to plan diets for healthy persons, and is set to cover the needs of almost everyone, but it leads the substantial overestimate of the prevalence of micronutrient inadequacy if applied to a population group.
Unlike macronutrients, which are proteins, fats, and carbohydrates, micronutrients are needed in milligram or microgram quantities but are critical for growth, immune function, brain development, and overall well-being.
Vitamins: Organic compounds that can be water-soluble (e.g., B vitamins, vitamin C) or fat-soluble (e.g., vitamins A, D, E, K).
Vitamins are crucial for energy production, immune defense, and blood clotting.
Minerals: Inorganic elements categorized as macrominerals-calcium, magnesium or trace minerals- iron, zinc.
Minerals support bone health, fluid balance, and metabolic processes.
Iron: Vital for oxygen transport and brain development; deficiency can cause anemia.
Vitamin A: Supports vision and immune function.
Iodine: Essential for thyroid function and cognitive development.
Zinc: Promotes immunity and proper growth.
Vitamin D: Important for bone health and immune response.
Micronutrients are obtained through a balanced diet rich in: Fruits and vegetables Whole grains Lean proteins Dairy products Nuts and seeds.
Deficiencies in micronutrients can lead to malnutrition and diseases such as anemia, scurvy, or developmental delays.
Excessive intake can cause toxicity.
Micronutrient deficiencies can have significant impacts on health:
Impaired Growth and Development: Deficiencies in iron, iodine, vitamin A, and zinc can lead to stunted growth, intellectual impairment, and developmental delays, particularly in children.
Micronutrient deficiencies weaken the immune system, increasing vulnerability to infections like diarrhea, measles, malaria, and pneumonia, especially critical for young children and pregnant women.
Inadequate intake of certain micronutrients (e.g., magnesium) is linked to chronic conditions such as cardiovascular disease, type 2 diabetes, and osteoporosis.
Pregnant women with deficiencies in folate or iodine face higher risks of birth defects, underweight babies, and maternal mortality.
Vitamin A deficiency can cause blindness and other eye disorders.
Lack of essential nutrients like iodine and iron can result in reduced cognitive function and lower productivity.
The long-term effects of micronutrient deficiencies:
Cognitive Impairment: Deficiencies in iron, iodine, and folate can lead to intellectual disabilities, reduced cognitive function, and lower educational outcomes.
Growth Retardation: Zinc and vitamin A deficiencies can result in stunted growth and delayed physical development in children.
Chronic Diseases: Persistent deficiencies in micronutrients like magnesium and vitamin D are linked to conditions such as cardiovascular disease, type 2 diabetes, osteoporosis, and metabolic disorders.
Vision Loss: Vitamin A deficiency is the leading cause of preventable blindness globally.
Weakened Immunity: Deficiencies in zinc, vitamin A, and iron compromise immune function, increasing susceptibility to infections such as diarrhea and respiratory diseases.
Folate and iodine deficiencies during pregnancy can cause neural tube defects, stillbirths, and other congenital anomalies.
Poor health due to micronutrient deficiencies reduces work capacity, productivity, and earning potential.
Deficiencies in pregnant women, such as folate, iron, and iodine, can lead to low birth weight, neural tube defects, and cognitive impairments in offspring.
Children born to mothers with micronutrient deficiencies are more likely to experience stunted growth, reduced cognitive abilities, and increased susceptibility to infections, which can hinder their long-term potential.
Poor maternal nutrition increases the risk of complications during childbirth and higher infant mortality rates.
Malnourished mothers are more likely to give birth to undernourished children, continuing the cycle of deficiencies across generations.
Breaking this cycle requires targeted interventions during critical periods like pregnancy and early childhood through supplementation, fortification, and dietary improvements, which have been proven to be highly effective in reducing micro nutrient deficiencies.
Fortification has significantly reduced deficiencies of iodine, vitamin A, iron, and folic acid.
Salt iodization has decreased goiter prevalence by 40%, and folic acid fortification has reduced neural tube defects by 40–50% globally.
Fortification is a low-cost intervention with broad public health benefits.
Increased Risk of Pregnancy Complications: Deficiencies in iron, folate, and vitamin D are linked to conditions such as anemia, gestational diabetes, and preeclampsia.
Iron deficiency, the most common during pregnancy, results from increased maternal and fetal demands.
Lack of essential nutrients like folate and iodine can cause neural tube defects, preterm birth, and low birth weight.
Vitamin A deficiency is also associated with higher maternal mortality rates.
Micronutrient deficiencies can weaken immunity and increase susceptibility to infections.
Overweight or obese women are particularly prone to deficiencies in vitamin B12, folate, and vitamin D, which further exacerbate health risks.
Vitamin B 12 is found only an animal sourced foods: milk, eggs, and fish.
People who practice the strictest types of vegetarianism-veganism need to take supplements or consume vitamin B 12 fortified foods such as fortified cereals.
B12 levels can also be low in persons who consume a lacto-ovo vegetarian diet, which includes eggs and dairy products and low levels of our common in low and middle income countries where intake of animal source foods is limited.
Consequences of maternal vitamin B 12 depletion include poor fetal storage of vitamin B 12 and low concentrations in milk that can result in serious developmental delays in infants.
Older adults have increased prevalence of B12 deficiency as vitamin B12 absorption is impaired with reduced production of gastric acid which is needed to release the vitamin from foods.
The risk of vitamin B deficiencies increased in individuals with malabsorption conditions or who have undergo gastric bypass surgery.