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It’s time for your annual check-up at the doctor’s office and that means it’s time for a blood test! We all go through these every year, some more than others, but do you really know what they’re testing for?

Most of the time they are making sure you don’t have any nutritional deficiencies!

A nutritional deficiency is when one is so low in a certain (or more than one) essential nutrient and the body becomes malnourished and diseased. We’re going over the most common nutritional deficiencies and breaking down what kind of symptoms you could experience if you’re suffering, how to avoid becoming deficient and what foods to include in your diet!

The Role Of Micronutrients

Vitamins support healthy immune function, hormone balancing, support skin, eye and bone health, are involved in the digestion process, aid in cellular energy and production and much, more! They are an essential nutrient and the body can produce some but, not all vitamins. They can be fat soluble, meaning they are stored in the body in the fat tissue or water-soluble, meaning they are not stored in the body but excreted through urine and sweat when the body doesn’t need it anymore.

Minerals help with the development of bones and teeth, are essential for hemoglobin production (read: blood), balance the fluid levels in the body, support healthy digestion and immune function, help the body get rid of free radicals, help with macronutrient metabolism and tons more!

The best way to get an adequate amount of vitamins and minerals is through proper nutrition. That means through healthy foods! Keep in mind that vitamins and minerals do not provide calories like carbohydrates, fats and protein do.

Most Common Nutritional Deficiencies


Iron deficiency is the most common nutritional deficiency in the world, affecting about 25% of the global population. Iron is the main component of the red blood cells, so it seems pretty scary that so many people are deficient, huh?

Symptoms that come with low iron levels are fatigue, weakness, impaired brain function and low energy. The health condition that can develop from having extremely low iron levels is called anemia.

The reason iron deficiency is common is that iron can be difficult to absorb and subsequently used by the body. The best source of iron is called heme iron and is only found in red meat, shellfish, organ meats and shellfish. This can be a red flag for vegan and vegetarians, which is no wonder that many plant-based eaters suffer from low iron. Thankfully, non-heme iron can be found in beans, leafy greens such as spinach or kale and seeds. However, the amount of iron in these plant-based foods is much lower and less readily available to the body than heme iron. They are some ways to increase iron absorption through food, but we will get to that towards the end of the article!


Another very common nutrient deficiency is iodine. Iodine is essential for healthy thyroid function and assists in producing thyroid hormones such as T3 or T4. The thyroid is important in metabolism, bone maintenance, growth and a healthy reproductive system. About one-third of the population is deficient and the symptoms experienced are dry skin and mouth, weight gain, fertility problems, trouble breathing and a swollen thyroid gland.

Iodine is found in seaweed, fish, dairy, eggs and is added to table salt. However, it is not recommended to supplement heavily with iodine because too much in the body can cause more harm than food. (Do talk to your doctor if you think you may be deficient in iodine!)

Vitamin B12

Vitamin B12 is essential for blood formation and healthy brain and nerve function. It is only found in animal products, making it a common nutrient to be deficient in if you are vegan or vegetarian. The health condition when vitamin B12 levels get dangerously low is called megaloblastic anemia. Unlike some other B vitamins, the body cannot produce vitamin B12, making it essential to consume through food or supplementation. The body needs a certain protein, called intrinsic factor, to be absorbed properly, however, some people do not produce this protein, causing them to be deficient in it even if they eat animal products!

Vitamin B12 is found in meat, dairy, eggs and nutritional yeast. Since it is a water-soluble vitamin, the body will not store excess B12, meaning you should aim to consume some almost every day!

Vitamin D

This sunshine vitamin is another common nutrient that about 42% of the US population is deficient in. Vitamin D is a steroid hormone that can be difficult to absorb. The best source of Vitamin D is from the sun; however, the skin needs to be exposed for a certain amount time, meaning no sunscreen. That can be difficult to do with the dangers of skin cancer and all the sun protection going around. Children, elderly people, those with darker skin and people living in colder climates are the most likely to be short on Vitamin D. Symptoms experienced are reduced immune function and muscle/ bone weakness. Vitamin D helps carry calcium into the bones, which brings us to the next common nutritional deficiency…


It’s no secret that calcium is the most important mineral for bone and teeth development, but it also plays an essential role as a signalling molecule throughout the body. Calcium is stored in the bones and when the diet is short on calcium, the body will take some bones. If this happens often, over time, bones may weaken or break and even deteriorate, known as Osteoporosis.

In foods, calcium is found in dairy products, dark green vegetables like kale, collard greens and broccoli, in almonds and sesame seeds!
Vitamin And Mineral Pairing

Some vitamins and minerals need each other to work together in the body.

Vitamin C and Iron

Vitamin C helps with absorption of iron in the body. If you are consuming plant-based sources of iron such as spinach, try squeezing fresh lemon juice on it or having some red pepper with it.

Calcium and Vitamin D

Like mentioned above, vitamin D helps carry the calcium into the bones to keep them strong. A lot of dairy products are fortified with vitamin D, however, just aim to get enough of each nutrient in a day and you should be okay!

Calcium and Magnesium

These minerals work together to provide normal muscle function and cell membrane maintenance, build strong bones and teeth and help to relax the body

Why Are We So Deficient?

Glad you asked! The Standard American Diet (SAD) is high in refined carbohydrates, processed foods and convenience junk. Sure, these foods can be inexpensive and take little to no time to make, but most contain no vitamins and minerals what so ever!

If you want to prevent any nutritional deficiencies for you and your family, aim to consume mostly whole, natural foods. Leafy greens, antioxidant-rich fruit, colorful vegetables, lean proteins, nuts, seeds, beans and whole grains all contain a wide variety of vitamins and minerals.

Eating real food is important but don’t get into the habit of eating the same three healthy meals a day. Adding variety to your meals is recommended because it varies the types of vitamins and minerals your body is getting. An easy rule of thumb is: if you can grow or farm it, eat it. If it comes from a box or package, don’t!

For more information on this, we have a full article on using Nutrition as Medicine that goes much more in-depth.

Disclaimer: Please talk to a healthcare professional if you have any concerns about nutritional deficiencies or any symptoms you may be experiencing.

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