5 Most Common Nutrient Deficiencies

5 Most Common Nutrient Deficiencies

Remember, supplements are never a substitute for a balanced, healthful diet. While it’s possible to get most of them from a balanced diet, the typical Western diet is low in several very important nutrients.


19–50 years: Male 8 mg  Female 18 mg Pregnant 27 mg

Iron is an essential element for blood production. About 70 percent of your body’s iron is found in the red blood cells of your blood called hemoglobin and in muscle cells called myoglobin. Hemoglobin is essential for transferring oxygen in your blood from the lungs to the tissues.

According to WHO Iron deficiency is one of the most common nutrient deficiencies in the world, affecting more than 25% of people worldwide.

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.


  • Tiredness
  • Weakness
  • Pale skin
  • Cold hands and feet
  • Brittle nails
  • Weakened immune system
  • Impaired brain function

Two Main Sources of Iron

  • Heme iron – This type of iron is very well absorbed. It’s only found in animal foods, with red meat containing particularly high amounts.
    • Found in red meat, organ meats, shellfish, canned sardines. 
  • Non-heme iron – This type, found in both animal and plant foods, is more common. It is not absorbed as easily as heme iron.
    • Leafy greens; kale, spinach, broccoli
    • Beans
    • Seeds

Tip: 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.


The daily value (DV) for iodine is 150 mcg for adults and children aged 4. The upper limit is about 1,100 in adults before toxicity can occur however it is rare.

Iodine is most commonly associated with the thyroid. People with iodine deficiencies are prone to having hypothyroidism. What many people don’t know is that when you have hypothyroidism you most commonly will develop a goiter. A goiter is an enlarged thyroid. In hypothyroidism tour TSH is high and your T3 and T4 are low.

Signs and Symptoms

  • Goiter
  • Fatigue and weaknesses
  • Weight gain
  • Hair loss, dry and flaky skin
  • Trouble learning or remembering
  • Feeling cold all the time

Main sources of iodine

  • Seaweed has the highest concentration of iodine, 1 gram of kelp has over 500% of the daily value
  • Fish: about 3-4 ounces can provide about 50-60% of DV
  • Dairy: about 1 cup of plain yogurt can get you 50% of the DV
  • Eggs: about 1 large egg can get you 16% DV

Vitamin D

Vitamin D intake is recommended at 400–800 IU/day or 10–20 micrograms. However, some studies suggest that a higher daily intake of 1000–4000 IU (25–100 micrograms) is needed to maintain optimal blood levels.

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.

Unfortunately, about 42% of the US population is vitamin D deficient with some populations having even higher levels of deficiency, including premenopausal women, those with poor nutrition habits, people over age 65, Caucasians who avoid even minimal sun exposure, and those who take prescription medication long term.

Symptoms of Vitamin D are not noticeable and take years to develop. 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 (rickets)

The best source of Vitamin D is sunlight. Supplemental can be found in Cod liver oil, fatty fish, and egg yolk. One large egg yolk contains 7% of the DV

Note that screening for Vitamin D deficiency is not part of the standard protocol in the US

Vitamin D & COVID

There is historic evidence that vitamin D supplementation prevented past respiratory virus pandemics. Molecular mechanisms of vitamin D action can prevent respiratory viral infections and protect against ARDS. Vitamin D’s direct effect on the renin-angiotensin-system (RAS), which in concert with additional effects, can modify host responses thus preventing a cytokine storm and SARS-CoV-2-induced pathological changes.

The study, titled “Estimated Inactivation of Coronaviruses by Solar Radiation,” looked at how effective UVB rays had been at inactivating coronavirus at various locations around the world.

90% or more of SARS-CoV-2 virus will be inactivated after being exposed to 11-34 minutes of midday sunlight in most US and world cities during summer.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7300806/

Vitamin B12

Recommended DV of vitamin B12 for people above the age of 14 is 1.8 – 2.4. B12 should be slightly increased during pregnancy and lactation.

Vitamin B 12 is a water-soluble vitamin responsible for red blood cell formation, brain function, and nerve function. Vitamin B12 is found in animal food, this is why it is important for vegetarians and vegans to take a Vitamin B 12 supplements.

It is interesting to understand that vitamin B12 is absorbed differently and it needs a protein called intrinsic factor. People that lack this need to get B12 injections or higher doses of B12.

Signs and Symptoms

  • Megaloblastic anemia: blood disorder that lowers your RBC count while enlarging the RBC itself
  • Fatigue, weakness
  • Weight loss, loss of appetite
  • Constipation

Main sources of Vitamin B12

  • Shellfish: 3 oz of clams accounts for over 1000% of DV
  • Organ meats: about 2oz of the liver has 1000% DV
  • Meats: 6oz of beef can offer over 100% of DV


The DV of calcium of adults and children above the age of 4 is 1,300 mg

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. 

Vitamin D helps with the absorption of calcium and phosphorus.

What many people don’t know about calcium is that it is also a signal molecule. Without calcium your heart can’t beat, your muscles can’t contract or relax, and your nerves can’t communicate. Your calcium is regulated in the blood if you have too much it is stored in your bones, if you have too little it is released from your bones.  

Signs and Symptoms

  • Osteoporosis: think of porous bone. Calcium gets pulled from the bone leading to weak and brittle bones
  • Rickets: softening and weakening of bones in children
  • Brittle nails, numbness in hands and feet
  • Muscle spasms and cramps
  • Changes in HR and rhythm and blood pressure
  • Increased incidence of fractures

Main Sources of Calcium

  • Boned fish. One can of sardines is about 40% of DV
  • Dairy: 1 cup of milk is about 33% of DV
  • Dark leafy greens: 1 oz of kale has about 5% DV
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