How will I know if I’m nutrient deficient?
PART 2 / 3 (Catch up by reading PART 1 ‘Are you nutrient deficient and don’t know it?’ if you haven’t already)
There are 3 reasons why being nutrient deficient isn’t that obvious:
It may be hard to tell if you are nutrient deficient just by looking at your symptoms. Initially, nutritional deficiency symptoms may not manifest at all. Or, if you have any, they are likely mild ones that almost everyone has sometimes like fatigue, brain fog, poor sleep, and digestive or skin issues. Most people don’t know that these common symptoms, which can have many different causes, can be caused by a nutrient deficiency.
With the exception of iron and vitamin D, doctors and other health professionals rarely test for nutrient deficiencies. The last time you visited a doctor, did they do a full blood test for minerals and vitamins such as magnesium, selenium, zinc, copper, folate, B12, C, D, and E? Even most functional and integrative medicine doctors don’t do this. (Mostly because they are not covered by insurance. Not to mention that most doctors and nurses don’t know how to read the tests properly.)
We’ve been led to believe (incorrectly) that vitamin deficiencies only occur in poor countries and not in the first world, like the US, Canada, and the UK. Unfortunately, this is completely false. A startlingly large number of people in the United States don’t get enough nutrition.
The shockingly high number of people in the US who don’t get enough nutrition
The table below summarizes data on nutritional status in the US from the Linus Pauling Institute
Nutrient | % of population deficient |
vitamin C | 39% |
vitamin A | 43% |
calcium | 44% |
vitamin K | 67% |
vitamin E | 89% |
choline | 92% |
vitamin D | 94% |
magnesium | 95% |
potassi um | 100% |
The NHANES 2007-2010 survey of 16,444 people in the US aged 4 and up where they discovered that many of them were deficient in several micronutrients confirms the data above.
Bioavailability is key but often ignored
The amount of a nutrient that is taken in and then released into the bloodstream so that the body can use it is referred to as its bioavailability. Almost always, the amount of bioavailable nutrients in a food is less than the total amount of nutrients.
For example, only 5% of the calcium in spinach is absorbed by the body. Even though one serving of spinach contains around 115 mg of calcium, only 6 mg is actually absorbed. So, to get the same amount of bioavailable calcium as a glass of milk, you’d need 16 cups of spinach!

Three factors influence how easily nutrients are absorbed from food:
- The form of the nutrient?
- The presence of additional nutrients that improve bioavailability (synergy)
- Whether there are anti-nutrients and nutrient inhibitors present in the food.
The ability of the body to absorb nutrients is heavily influenced by how they are produced.
Heme iron is much easier to obtain than nonheme iron, which is found only in animal products such as meat and chicken. Heme iron is absorbed in amounts ranging from 15% to 35%, while nonheme iron is absorbed in amounts ranging from 2% to 20%.
The presence (or absence) of other nutrients can also affect how well nutrients are absorbed.
Nutrients often need each other to be effective. Iron can only enter cells if there is sufficient copper. Magnesium is required to activate vitamin D. (Even if you get enough vitamin D from the sun or pills, you may still be deficient if you don’t get enough magnesium, which activates vitamin D.) another example is that Vitamin C aids iron absorption in the digestive system.
Anti-nutrients and nutrient inhibitors reduce the bioavailability of nutrients in food.
Phytate is an antinutrient found in high concentrations in grains and legumes. It sticks to calcium, iron, and zinc and keeps the body from taking them in. When you consider all of these things, it’s clear that the RDA doesn’t often give us enough of the nutrients we need for good health. So, the real rates of nutritional deficiency are much higher than what the Linus Pauling Institute says.
Hidden Hunger, why are most people nutrient deficient?
How do nutritional gaps occur so frequently?
Since we’ve established that most people are deficient in a variety of minerals, the next logical question is, “Why?” After all, this is occurring in the world’s wealthiest countries. How is it possible that so many people in developed countries are still deficient in vitamins and minerals? a phenomenon sometimes called “hidden hunger.”
The amount of calories consumed in the United States has steadily increased over the last 50 years. The average number of calories Americans eat each day has gone up from 2,880 in 1961 to over 3,600, which is a 24 percent rise. Worse, the average American gets about 60% of their calories from highly processed foods like soda, sweets, pizza, bread, and fast food. These foods lack the nutrients and compounds that we need to stay healthy and strong and fight disease. We could be said to be well-fed but starving!
Deterioration of our soils

Chemical fertilizers, herbicides, and pesticides have altered the soil’s “microbiome” over the last few decades. As a result, eating plants or animals that ate plants also provides us with less nutrition. This is because it makes it more difficult for plants to absorb nutrients from the soil.
The number of vitamins and minerals in 43 different vegetables and fruits decreased significantly between 1950 and 1999, according to USDA data. Calcium, iron, potassium, and vitamin A levels all decreased by 27% between 1930 and 1980, according to research from the UK. According to one study, to get the same amount of nutrients as our forefathers, we would need to eat eight oranges today.
Increasing levels of toxicity in our food
Heavy metals and glyphosate, two toxins that are increasingly appearing in our food, make it difficult to obtain nutrients in a variety of ways. Glyphosate, for example, prevents the bacteria in our guts from producing and absorbing important nutrients such as folate, glycine, vitamin E, and vitamin K. Also, glyphosate moves minerals such as copper, iron, and selenium to the wrong places in our bodies, resulting in both mineral deficiency and toxicity.
Other research has also found that heavy metals such as mercury, lead, cadmium, and arsenic make it difficult for the body to absorb nutrients.
The industrial food system has gone global

The majority of fruits and vegetables sold in big-box stores come from hundreds or even thousands of miles away. This is especially true if you eat foods that are out of season in your area (like a banana in mid-winter in New York).
The typical carrot on your dinner plate today has traveled 1,838 kilometers. The issue is that once the food is picked, its nutritional value begins to decline. Red peppers, tomatoes, apricots, peaches, and papayas all have more vitamin C when picked and ripe from the plant.
Buying local broccoli in season from a supermarket will contain twice as much vitamin C as buying it out of season from another country.
Medications
Many over-the-counter and prescription medications make it more difficult for nutrients to enter the body. It is well known that taking metformin for diabetes causes a decrease in vitamin B12.
PPIs or anti-acids, which are prescribed for acid reflux, increase the risk of vitamin and mineral deficiencies, particularly vitamin B12, vitamin C, calcium, iron, and magnesium.
Your body loses magnesium, selenium, zinc, folate, and vitamins B2, B6, B12, C, and E when you use oral contraceptives. Because most doctors are unaware of these side effects, they do not advise their patients on how to avoid them.
Chronic Disease has gone rampant

Six out of every ten Americans now suffer from a chronic illness, and four out of every ten suffer from more than one. Chronic diseases that make it difficult for the body to absorb nutrients also make it difficult for the body to use them.
Obesity, as mentioned earlier in Part 1, can make it more difficult to produce vitamin D in the skin when exposed to sunlight or absorb vitamin D from food and supplements. People with autoimmune thyroid diseases may require more selenium than those with normal thyroid function.
Small intestine bacterial overgrowth, for example, makes it more difficult to break down nutrients like vitamin B12 (SIBO).
How to Restore Your Nutrient Deficiency
Read PART 3 to find out how to fill our deficiency gaps.
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