Many nutrients are essential for good health.
While it’s possible to get most of them from a balanced diet, the typical Western diet is low in several very important nutrients.
1. IRON DEFICIENCY
Iron is an essential mineral.
It’s a large component of red blood cells, in which it binds with hemoglobin and transports oxygen to your cells.
Iron deficiency is one of the most common nutrient deficiencies in the world, affecting more than 25% of people worldwide.
This number rises to 47% in preschool children. Unless they're given iron-rich or iron-fortified foods, they are very likely to lack iron.
Around 30% of menstruating women may be deficient as well due to monthly blood loss, and up to 42% of young, pregnant women may be deficient as well.
Additionally, vegetarians and vegans have an increased risk of deficiency because they consume only non-heme iron, which is not absorbed as well as heme iron.
The most common consequence of iron deficiency is anemia, in which the number of your red blood cells and your blood’s ability to carry oxygen drops.
Symptoms usually include tiredness, weakness, a weakened immune system, and impaired brain function.
However, you should never supplement with iron unless you truly need it. Too much iron can be very harmful.
Notably, vitamin C can enhance the absorption of iron. Eating vitamin-C-rich foods like oranges, kale, and bell peppers alongside iron-rich foods can help maximize your iron absorption.
2. IODINE DEFICIENCY
Iodine is an essential mineral for normal thyroid function and the production of thyroid hormones.
Thyroid hormones are involved in many bodily processes, such as growth, brain development, and bone maintenance. They also regulate your metabolic rate.
Iodine deficiency is one of the most common nutrient deficiencies, affecting nearly a third of the world's population.
The most common symptom of iodine deficiency is an enlarged thyroid gland, also known as a goiter. It may also cause an increase in heart rate, shortness of breath, and weight gain.
Severe iodine deficiency is linked to serious harm, especially in children. It may cause mental retardation and developmental abnormalities.
However, these amounts can vary greatly. As iodine is found mostly in soil and ocean water, iodine-poor soil will result in low-iodine food.
Some countries mandate the enrichment of table salt with iodine, which has successfully reduced the incidence of deficiencies.
3. VITAMIN D DEFICIENCY
Vitamin D is a fat-soluble vitamin that functions like a steroid hormone in your body.
It travels through your bloodstream and into cells, telling them to turn genes on or off. Almost every cell in your body has a receptor for vitamin D.
Vitamin D is produced from cholesterol in your skin upon exposure to sunlight. Thus, people who live far from the equator are likely to be deficient unless their dietary intake is adequate or they supplement with vitamin D.
Adults who are deficient in vitamin D may experience muscle weakness, bone loss, and an increased risk of fractures. In children, it may cause growth delays and soft bones.
Also, vitamin D deficiency may play a role in reduced immune function and an increased risk of cancer.
4. VITAMIN B12 DEFICIENCY
Vitamin B12, also known as cobalamin, is a water-soluble vitamin.
It is essential for blood formation, as well as brain and nerve function.
Every cell in your body needs B12 to function normally, but your body is unable to produce it. Therefore, you must get it from food or supplements.
B12 is only found in sufficient amounts in animal foods, although certain types of seaweed may provide small quantities. Therefore, people who do not eat animal products are at an increased risk of deficiency.
Studies indicate that up to 80 to 90% of vegetarians and vegans may be deficient in vitamin B12.
More than 20% of older adults may also be deficient in this vitamin since absorption decreases with age.
B12 absorption is more complex than that of other vitamins because it’s aided by a protein known as intrinsic factor. Some people are lacking in this protein and may thus need B12 injections or higher doses of supplements.
One common symptom of vitamin B12 deficiency is megaloblastic anemia, which is a blood disorder that enlarges your red blood cells.
Other symptoms include impaired brain function and elevated homocysteine levels, which is a risk factor for several diseases.
5. CALCIUM DEFICIENCY
Calcium is essential for every cell in your body. It mineralizes bones and teeth, especially during times of rapid growth. It is also very important for bone maintenance.
Additionally, calcium serves as a signaling molecule. Without it, your heart, muscles, and nerves would not be able to function.
The calcium concentration in your blood is tightly regulated, and any excess is stored in bones. If your intake is lacking, your bones will release calcium.
That is why the most common symptom of calcium deficiency is osteoporosis, characterized by softer and more fragile bones.
Although supplementing increased these numbers slightly, most people were still not getting enough calcium.
Symptoms of more severe dietary calcium deficiency include soft bones (rickets) in children and osteoporosis, especially in older adults.
Some studies demonstrate an increased risk of heart disease in people taking calcium supplements, although other studies have found no effects.
While it’s best to get calcium from food rather than supplements, these supplements seem to benefit people who are not getting enough in their diet.
6. VITAMIN A DEFICIENCY
Vitamin A is an essential fat-soluble vitamin. It helps form and maintain healthy skin, teeth, bones, and cell membranes. Furthermore, it produces eye pigments, which are necessary for vision.
However, vitamin A deficiency is very common in many developing countries. About 44 to 50% of preschool-aged children in certain regions have vitamin A deficiency. This number is around 30% in Indian women.
Vitamin A deficiency can cause both temporary and permanent eye damage and may even lead to blindness. In fact, this deficiency is the world's leading cause of blindness.
Vitamin A deficiency can also suppress immune function and increase mortality, especially among children and pregnant or breastfeeding women.
While it is very important to consume enough of this vitamin, too much preformed vitamin A may cause toxicity.
This does not apply to pro-vitamin A, such as beta carotene. High intake may cause your skin to turn slightly orange, but this effect isn’t dangerous.
7. MAGNESIUM DEFICIENCY
Magnesium is a key mineral in your body.
Essential for bone and teeth structure, it’s also involved in more than 300 enzyme reactions.
Low intake and blood levels of magnesium are associated with several conditions, including type 2 diabetes, metabolic syndrome, heart disease, and osteoporosis.
Deficiency may be caused by disease, drug use, reduced digestive function, or inadequate magnesium intake.
The main symptoms of severe magnesium deficiency include abnormal heart rhythm, muscle cramps, restless leg syndrome, fatigue, and migraines.
More subtle, long-term symptoms that you may not notice include insulin resistance and high blood pressure.