Many nutrients are absolutely essential for good health. It is possible to get most of them from a balanced, real food-based diet.
However, the typical modern diet lacks several very important nutrients.
This article lists 7 nutrient deficiencies that are incredibly common.
1. Iron Deficiency
Iron deficiency is very common, especially among young women, children and vegetarians. It may cause anemia, tiredness, weakness, weakened immune system and impaired brain function.
The best dietary sources of non-heme iron include:
- Beans: Half a cup of cooked kidney beans (3 ounces or 85 g) provides 33% of the RDI.
- Seeds, such as pumpkin, sesame and squash seeds: One ounce (28 g) of roasted pumpkin and squash seeds provide 11% of the RDI.
- Broccoli, kale and spinach: One ounce (28 g) of fresh kale provides 5.5% of the RDI.
Vitamin C can enhance the absorption of iron. Eating vitamin C-rich foods like oranges, kale and bell peppers along with iron-rich foods can help maximize iron absorption.
2. Iodine Deficiency
Iodine is one of the most common nutrient deficiencies in the world. It may cause enlargement of the thyroid gland. Severe iodine deficiency can cause mental retardation and developmental abnormalities in children.
Thyroid hormones are involved in many processes in the body, such as in growth, brain development and bone maintenance. They also regulate the metabolic rate.
There are several good dietary sources of iodine:
- Seaweed: Only 1 g of kelp contains 460–1000% of the RDI.
- Fish: 3 ounces (85 g) of baked cod provide 66% of the RDI.
- Dairy: One cup of plain yogurt provides about 50% of the RDI.
- Eggs: One large egg provides 16% of the RDI.
However, keep in mind that these amounts can vary greatly. Iodine is found mostly in the soil and the sea, so if the soil is iodine-poor then the food growing in it will be low in iodine as well.
Some countries have responded to iodine deficiency by adding it to salt, which has successfully reduced the severity of the problem.
3. Vitamin D Deficiency
Vitamin D is a fat-soluble vitamin that works like a steroid hormone in the body.
It travels through the bloodstream and into cells, telling them to turn genes on or off.
Almost every cell in the body has a receptor for vitamin D.
Vitamin D is produced out of cholesterol in the skin when it is exposed to sunlight. So people who live far from the equator are highly likely to be deficient, since they have less sun exposure.
Adults who are deficient in vitamin D may experience muscle weakness, bone loss and 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.
Unfortunately, very few foods contain significant amounts of this vitamin.
People who are truly deficient in vitamin D may want to take a supplement or increase their sun exposure. It is very hard to get sufficient amounts through diet alone. Blood levels should be maintained around 50 – 70 ng/ml and supplementation should be 2000 – 5000 IU/day.
4. Vitamin B12 Deficiency
Vitamin B12 deficiency is very common, especially in vegetarians and the elderly. The most common symptoms include a blood disorder, impaired brain function and elevated homocysteine levels.
5. Calcium Deficiency
Calcium is essential for every cell. It mineralizes bone and teeth, especially during times of rapid growth. It is also very important for the maintenance of bone.
Additionally, calcium plays a role as a signaling molecule all over the body. Without it, our heart, muscles and nerves would not be able to function.
The calcium concentration in the blood is tightly regulated, and any excess is stored in bones. If there is lack of calcium in the diet, calcium is released from the bones.
That is why the most common symptom of calcium deficiency is osteoporosis, characterized by softer and more fragile bones.
One survey found that in the US, less than 15% of females aged 9–18 and less than 10% of women over 50 met the recommended calcium intake.
In the same survey, less than 22% of teenage boys aged 9–13 and men over 50 met the recommended calcium intake from diet alone. Supplement use increased these numbers slightly, but the majority of people still were not getting enough calcium.
Symptoms of more severe dietary calcium deficiency include soft bones (rickets) in children and osteoporosis, especially in the elderly.
Dietary sources of calcium include:
- Boned fish: One can of sardines contains 44% of the RDI.
- Dairy products: One cup of milk contains 35% of the RDI.
- Dark green vegetables, such as kale, spinach, bok choy and broccoli: One ounce of fresh kale provides 5.6% of the RDI.
The effectiveness and safety of calcium supplements have been somewhat debated in the last few years.
Some studies have found an increased risk of heart disease in people taking calcium supplements, although other studies have found no effects.
Although it is best to get calcium from food rather than supplements, calcium 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 fat membranes.
Furthermore, it produces our eye pigments – which are necessary for vision.
While it is very important to consume enough vitamin A, it is generally not recommended to consume very large amounts of preformed vitamin A, as it may cause toxicity.
This does not apply to pro-vitamin A, such as beta-carotene. High intake may cause the skin to become slightly orange, but it is not dangerous.
7. Magnesium Deficiency
Magnesium is a key mineral in the body.
It is essential for bone and teeth structure, and is also involved in more than 300 enzyme reactions.
Low intake and blood levels of magnesium have been associated with several diseases, including type 2 diabetes, metabolic syndrome, heart disease and osteoporosis.
The main symptoms of severe magnesium deficiency include arrhythmias, muscle cramps, restless leg syndrome, fatigue and migraines
More subtle, long-term symptoms that you may not notice include insulin resistanceand high blood pressure.
Dietary sources of magnesium include:
- Whole grains: One cup of oats (6 ounces or 170 g) contains 74% the RDI.
- Nuts: 20 almonds provide 17% of the RDI.
- Dark chocolate: 1 ounce (30 g) of dark chocolate (70–85%) provides 15% of the RDI.
- Leafy, green vegetables: 1 ounce (30 g) of raw spinach provides 6% of the RDI.
Take Home Message
It is possible to be deficient in almost every nutrient, but these 7 are by far the most common.
Children, young women, the elderly and vegetarians seem to be at the highest risk of several deficiencies.
The best way to prevent a deficiency is to eat a balanced, real food-based diet that includes nutrient-dense foods (both plants and animals).
However, supplements are necessary when it is impossible to get enough from the diet alone.
Stay Healthy.
