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The Reality of Nutrient Deficiencies

Posted by Issac Ishak on

How common are nutrient deficiencies?

Well… If I’m being honest you probably have one no matter how good you think your diet is. This doesn’t mean that supplements are the first line of defense. The truth is, vitamins, minerals, and phytochemicals found in real food and dose per dose, they often outperform those found in pills and capsules— but utilizing supplements to fulfill things we’re lacking through our diet is an effective way when it comes to the management of nutritional deficiencies.

If you’re not following a sound eating protocol that’s designed specifically to improve your relationship with food or nutrient deficiencies, you’d better get to cracking. The longer you wait, the more at risk you become for a laundry list of nutritional deficiency-related diseases or disorders. Diseases and disorders you could have prevented by changing a few eating habits.

The other day I was searching databases for diet analysis studies— my goal was to find studies done on athletes, recreational exercisers (is that a word?), and sedentary individuals.

Misner, Bill. “Food alone may not provide sufficient micronutrients for preventing deficiency.” Journal of the International Society of Sports Nutrition vol. 3,1 51-5. 5 Jun. 2006

This twenty-subject dietary analysis study is NOT representative of the entire population, however, the results supported begs the question:

Does food selection alone provide 100% of the former RDA or newer RDI micronutrient requirements?

In this specific analysis those who were in a calorie deficit, or energy-restricted state tended to record a greater number of micronutrient deficiencies as compared to the calorie-sufficient diets.

Of the 340 micronutrient entries generated from 17 micronutrients analyzed, all 20 subjects presented between 3 and 15 deficiencies each based on the Recommended Daily Allowances (RDA) value from food intake alone.

Males averaged deficiencies in 40% of the vitamins and 54.2% of the minerals required. The male group was RDA-deficient in 78 out of 170 micronutrient entries, or 45.8% of the 10 vitamins and 7 minerals analyzed.

Females averaged deficiencies in 29% of the vitamins and 44.2% of the minerals Recommended Daily Allowances (RDA) required. The female group was RDA-deficient in 60 out of 170 micronutrients or 35.2% of the 10 vitamins and 7 minerals analyzed.

Both male and females, recorded 138 micronutrient deficiencies out of the possible 340 micronutrients analyzed, or 40.5% micronutrient RDA-deficiency from food intake alone.

I don’t know about you, but that’s pretty shocking. Some interesting things to note and although this is one study it further begs the question... Nutritional deficiencies might not seem like something serious, but they can develop into something serious overtime. 

Common Nutritional Deficiencies 

1. Iron

Iron is an essential mineral. It’s a large component of red blood cells, in which it binds with hemoglobin and transports fresh oxygen to your cells. The two types of dietary iron are:

  • Heme iron. This type of iron is very well absorbed. It’s only found in animal foods, with red meat containing particularly high amounts.
  • Non-heme iron. This type, found in both animal and plant foods, is more common, but has lower absorption/bio-avalibility than heme.

Iron deficiency is one of the most common nutrient deficiencies in the world, affecting more than 25% of people worldwide (12). This number rises to 47% in preschool children. Unless they're provided with iron-rich or iron-fortified foods, they’re 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 (34). 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 lethargy, fatigue, compromised immune system, and impaired cognitive function (56). The best dietary sources of heme iron include:

  • Red meat. 3 ounces (85 grams) of ground beef provide almost 30% of the Daily Value (DV).
  • Organ meat. One slice (81 grams) of liver gives more than 50% of the DV.
  • Shellfish. Clams, mussels, and oysters are excellent sources of heme iron, with 3 ounces (85 grams) of cooked oysters packing roughly 50% of the DV.
  • Canned sardines. One 3.75-ounce (106-gram) can offer 34% of the DV.

The best dietary sources of non-heme iron include:

  • Beans. Half a cup (85 grams) of cooked kidney beans provides 33% of the DV.
  • Seeds. Pumpkin, sesame, and squash seeds are good sources of non-heme iron. One ounce (28 grams) of roasted pumpkin or squash seeds contains 11% of the DV.
  • Dark, leafy greens. Broccoli, kale, and spinach are rich in iron. One ounce (28 grams) of fresh kale provides 5.5% of the DV.

However, you should never supplement with iron unless you truly need it. Too much Iron can be very harmful and can result in Hemochromatosis. 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/bio-availability.

2. Iodine

Iodine is an essential mineral essential for normal thyroid function and the production of thyroid hormones (8). 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 (91011). The most common symptom of iodine deficiency is an enlarged thyroid gland, also known as a Goiter. It may also result in an increase in heart rate (HRV), shortness of breath, and weight gain (8). Severe iodine deficiency is linked to serious harm, especially in children. It can contribute to the development of mental retardation and other developmental abnormalities (810). Dietary sources of Iodine include:

  • Seaweed. Only 1 gram of kelp packs 460–1,000% of the DV.
  • Fish. Three ounces (85 grams) of baked cod provide 66% of the DV.
  • Dairy. One cup (245 grams) of plain yogurt offers about 50% of the DV.
  • Eggs: One large egg contains 16% of the DV.

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 (12). Iodine is one of the most common nutrient deficiencies in the world.

3. Vitamin D

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 exposed to less daylight are more likely to be deficient unless their dietary intake is adequate or unless they supplement with vitamin D (1314). In the United States, about 42% of people may be deficient in this vitamin. This number rises to 74% in older adults and 82% in people with dark skin since their skin produces less vitamin D in response to sunlight (1516). Vitamin D deficiency is not usually obvious, as its symptoms are subtle and may develop over years or decades (1718). Adults who are deficient in vitamin D may experience muscle fatigue (hypertonia), bone loss (osteoporosis), and an increased risk of fractures. In children, it may cause growth delays and soft bones (rickets) (172021). Also, vitamin D deficiency may play a role in reduced immune function and an increased risk of cancer (22). While very few foods contain significant amounts of this vitamin, the best dietary sources are:

  • Cod liver oil. A single tablespoon (15 ml) packs 227% of the DV.
  • Fatty fish. Salmon, mackerel, sardines, and trout are rich in vitamin D. A small, 3-ounce (85-gram) serving of cooked salmon provides 75% of the DV.
  • Egg yolks. One large egg yolk contains 7% of the DV.

People who are deficient may want to take a supplement or increase their sun exposure. It is hard to get sufficient amounts through diet alone.

4. Vitamin B12 deficiency

Vitamin B12, also known as cobalamin, is a water-soluble vitamin, it's essential for blood formation, as well as brain and nerve function. Every cell in your body needs B12 to function optimally, 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 sources, but 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 80–90% of vegetarians and vegans may be deficient in vitamin B12 (2425). More than 20% of older adults may also be deficient in this vitamin since absorption decreases with age (262728). 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 b-12 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 (2930). Dietary sources of vitamin B12 include:

  • Shellfish. Clams and oysters are rich in vitamin B12. A 3-ounce (85-gram) portion of cooked clams provides 1,400% of the DV.
  • Organ meat. One 2-ounce (60-gram) slice of liver packs more than 1,000% of the DV.
  • Meat. A small, 6-ounce (170-gram) beef steak offers 150% the DV.
  • Eggs. One whole egg provides about 6% of the DV.
  • Milk products. One cup (240 ml) of whole milk contains about 18% of the DV.

Vitamin B12 isn’t considered harmful in large amounts because it’s often poorly absorbed and easily excreted. Vitamin B12 deficiency is very common, especially in vegetarians, vegans, and older adults. The most common symptoms include blood disorders, impaired brain function, and elevated homocysteine levels.


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 with the help of the parathyroid hormone. That is why the most common symptom of calcium deficiency is osteoporosis, characterized by softer and more fragile bones. One survey in the United States found that fewer than 15% of teenage girls, fewer than 10% of women over 50, and fewer than 22% of teenage boys and men over 50 met the recommended calcium intake (31). 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 (3233). Dietary sources of calcium include:


  • Boned fish. One can (92 grams) of sardines contains 44% of the DV.
  • Dairy products. One cup (240 ml) of milk provides 35% of the DV.
  • Dark green vegetables. Kale, spinach, bok choy, and broccoli are rich in calcium. Just 1 ounce (28 grams) of fresh kale offers 5.6% of the DV.

The effectiveness and safety of calcium supplements have been somewhat debated in the last few years. Some studies demonstrate an increased risk of heart disease in people taking calcium supplements, although other studies have found no effects (343536). 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 (37).


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 (38). There are two different types of dietary vitamin A:

  • Preformed vitamin A. This type of vitamin A is found in animal products like meat, fish, poultry, and dairy.
  • Pro-vitamin A. This type is found in plant-based foods like fruits and vegetables. Beta carotene, which your body turns into vitamin A, is the most common form.

More than 75% of people who eat a Western diet get more than enough vitamin A and do not need to worry about deficiency (39). However, vitamin A deficiency is very common in many developing countries. About 44–50% of preschool-aged children in certain regions have vitamin A deficiency. This number is around 30% in women (4041). 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 (40). Dietary sources of preformed vitamin A include:

  • Organ meat. One 2-ounce (60-gram) slice of beef liver provides more than 800% of the DV.
  • Fish liver oil. One tablespoon (15 ml) packs roughly 500% of the DV.

Dietary sources of beta carotene (pro-vitamin A) include:

  • Sweet potatoes. One medium, 6-ounce (170-gram) boiled sweet potato contains 150% of the DV.
  • Carrots. One large carrot provides 75% of the DV.
  • Dark green, leafy vegetables. One ounce (28 grams) of fresh spinach provides 18% of the DV.

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. Vitamin A deficiency is very common in many developing countries. It may cause eye damage and blindness, as well as suppress immune function and increase mortality among women and children.

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 (42). Almost half of the U.S. population consumes less than the required amount of magnesium (43). Low intake and blood levels of magnesium are associated with several conditions, including type 2 diabetes, metabolic syndrome, heart disease, and osteoporosis (4344). Low levels are particularly common among hospitalized patients. Some studies find that 9–65% of them are deficient (454647). Deficiency may be caused by disease, drug use, reduced digestive function, or inadequate magnesium intake (48). The main symptoms of severe magnesium deficiencies include abnormal heart rhythm, muscle cramps, restless leg syndrome, fatigue, and migraines (495051). More subtle, long-term symptoms that you may not notice include insulin resistance and high blood pressure. Dietary sources of magnesium include:

  • Whole grains. One cup (170 grams) of oats contains 74% of the DV.
  • Nuts. Twenty almonds pack 17% of the DV.
  • Dark chocolate. One ounce (30 grams) of dark chocolate offers 15% of the DV.
  • Dark green, leafy vegetables. One ounce (30 grams) of raw spinach provides 6% of the DV.

Magnesium deficiency is common and low intake is associated with many health conditions and diseases.

The bottom line...

It is possible to be deficient in almost every nutrient. That said, the deficiencies listed above are by far the most common. Children, young women, older adults, vegetarians, and vegans seem to be at the highest risk of several deficiencies. The best way to prevent deficiency is to eat a balanced diet that includes whole, nutrient dense foods. However, supplements may be necessary for those who can’t obtain enough from diet alone.

As professionals, we have to hold ourselves to higher standards when it comes to communication and creating discussions around specific topics.

Simply stating that “A CALORIE DEFICIT IS THE ONLY WAY TO ACHIEVE FAT LOSS” is a confusing statement, it doesn’t invalidate the fact that macronutrients (in specific proportions), micronutrients, hormonal status, nutrient timing… are all variables that contribute to someone successfully achieving fat loss while maintaining health-- not sacrificing it.

You’re not going to applaud someone who is banging their head through a wall until they finally get through and although I have tons of respect for people who are willing to ‘grind hard’ the reality is there are more efficient and effective ways to approaching things. Together we need to be the change and lead with education and honesty.

Every meal is a short-term investment in how you feel/perform, mid-term investment in how you look, and long-term investment in your freedom from disease.

It’s easy to oversimplify nutrition into general recommendations, and buzzwords, but that’s not enough to help someone fix their eating habits and (ultimately) get better results. Most people think they need a complete dietary overhaul when they start taking control of their nutrition. They go complete ‘Mission Impossible’ & start eliminating…

‘I have to cut out sugar & carbs’

‘More healthy fats/vegetables, no fruit’

‘I have to train & do cardio x6 days/wk’

A complete overhaul rarely addresses what’s making most people feel bad in the first place. Not obtaining the right nutrients in the right amounts will lead to dietary deficiencies. Performance during your session, rate of recovery, energy levels, appetite, mood, PROGRESS, all rely on getting essential nutrients daily. That’s why you can go keto, eat “clean”, vegan, go low carb or count calories, you can do “everything right” and still, feel crummy.

The first step is identifying the red flags 🚩 in your nutrition and building 🧱 better habits one by one.⠀

🚩 Common Red Flags 🚩

🔻Water (low-consumption, or dehydration)

🔻Vitamins/Minerals (vegetables/fruits/phytonutrients)

🔻Fiber (low-consumption)

🔻Protein (low-consumption)

🔻Essential fatty acids (EPA/DHA)

🧱 Better Habits 🧱

💦Drink more fluids.

🥗🍉Eat more veggies/fruits rich in vitamins, minerals, & phytonutrients

🍠🍓Eat more fiber-rich/quality carbs

🍗Eat more of the protein-rich foods

🐟Consume more essential/quality fat sources

It’s more than getting from point A to point B, how you feel in the process is just as important. You’re not trying to drive a car that’s on fire just to get to your destination. Once you’ve built better habits you can move on to more complex pieces to the puzzle.. but you can’t put the cart, before the horse & expect to succeed. The easy route is temporary and only exacerbates the issue once you see there’s no short-cut to get what you want. Health is wealth, don’t let your future self pay for the negligence you give your body today. When the goal is body composition related, the first thing on your to-do list should be restoring/optimizing your health.

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