By Dr. Mercola
Eating a balanced whole-food diet, such as described in my nutrition plan, is a foundational requirement for optimal nutrition. It can be quite difficult to get sufficient amounts of vitamins and minerals from your diet if you do not eat real food.
Unfortunately, even if you do eat well, how and where your food was grown can also influence your nutritional intake. Soil quality, for example, can significantly influence the levels of certain nutrients in your food, even if you eat organic.
Your age and certain health conditions (digestive issues and others) can also impact your body's ability to absorb and metabolize nutrients, potentially raising your risk for deficiencies, as can diets that restrict certain foods, such as strict vegan diets.
Below, I will review some of the most common vitamin and mineral deficiencies,1 and how to address them. Eating real food is usually your best bet, but sometimes supplementation may be advisable, especially if you're already experiencing signs of deficiency.
6 Most Common Vitamin and Mineral Deficiencies
Studies from both the U.S.2,3,4,5,6 and the U.K.7 suggest a majority of people fail to get certain key vitamins and minerals from food alone. Topping this list are vitamins D, E, A, C, magnesium and calcium.
However, in my experience, the following nutrient deficiencies tend to have the most important impact on your health.
For even more in-depth information about the benefits of each of these vitamins and minerals, and how to optimize your levels, please see the corresponding hyperlinks provided.
Oily fish and mushrooms
Oily fish; nuts, especially cashews and Brazil nuts; seeds; legumes; brown rice; raw cacao; avocados; seaweed and dark leafy greens like spinach and Swiss chard
Most fruits and vegetables, particularly citrus fruit, strawberries and kiwi
Oily fish such as wild-caught Alaskan salmon, sardines and anchovies
Fermented foods such as natto and fermented vegetables like sauerkraut; certain cheeses; raw butter and kefir made from raw milk
Beans such as white beans and lima beans; deep greens such as spinach and broccoli; sweet potatoes; fruits such as cantaloupe, oranges, red grapefruit, plums and bananas; avocados and nuts and seeds
Looking at this chart, it's easy to see where the majority of problems stem from: a lack of oily fish, nuts, seeds, fermented foods and fresh vegetables in the diet.
This chart also hints at important interactions between different nutrients. Vitamins, A, D, K2, magnesium and calcium, for example, work in tandem with each other. If one is lacking, it will affect one or more of the others.
The Importance of Marine-Based Omega-3 Fats
Low concentrations of the animal-based omega-3 fats EPA and DHA8 are associated with an increased risk of death from all causes, and omega-3 deficiency has been revealed as the sixth biggest killer of Americans.
When your diet is lacking in these anti-inflammatory omega-3s, you set the stage for health problems such as cardiovascular disease, cancer, depression, Alzheimer's, rheumatoid arthritis and diabetes, just to name a few.
Along with probiotics, B vitamins, magnesium, vitamin D and zinc, omega-3 fats are also among the most common vitamin and mineral deficiencies associated with attention deficit disorder (ADD) and attention deficit/hyperactivity disorder (ADHD).9
Telltale signs of omega-3 deficiency include dry, flaky skin, "chicken skin" on the back of your arms, dandruff or dry hair, soft brittle nails, fatigue, menstrual cramps and poor attention span.
Sardines and anchovies are one of the most concentrated sources of omega-3 fats,10 with one serving containing more than 50 percent of your recommended daily value.
They also contain other nutrients that many are deficient in, such as vitamin B12, calcium and choline. It's best to purchase them in water, not in olive oil, as nutritionally inferior versions of olive oil are used in canned fish.
If you decide to take omega-3s in supplement form, I believe krill oil is superior to fish oil. The omega-3 in krill is attached to phospholipids that increase its absorption, which means you need less of it.
Nutrient Deficiencies Are Common Even Among Those Taking Supplements
Even WITH supplementation, intakes for certain nutrients fall short of the estimated requirements, and excessive intake of any given nutrient is extremely rare. As noted by the authors of one 2014 study:11
"Only 0 percent, 8 percent, and 33 percent of the population had total usual intakes of potassium, choline and vitamin K above the adequate intake when food and MVMM [multivitamin/mineral supplements] use was considered.
The percentage of the population with total intakes greater than the tolerable upper intake level (UL) was very low for all nutrients; excess intakes of zinc were the highest (3.5 percent) across the population of all of the nutrients assessed …"
Also, as noted by Medtech Boston:12
"On January 6, 2016, the U.S. Departments of Health and Human Services and of Agriculture released the 2015 [to] 2020 Dietary Guidelines for Americans …
Consistent with the above findings, the Guidelines identified potassium, dietary fiber, choline, magnesium, calcium and vitamins A, D, E and C as nutrients 'consumed by many individuals in amounts below the Estimated Average Requirement or Adequate Intake levels.'
And while the Guidelines state as a goal that people should 'meet nutritional needs primarily through foods,' they also recognize that dietary supplements are 'useful in providing one or more nutrients that otherwise may be consumed in less than recommended amounts …'"
Optimizing Your Vitamin D Can Go a Long Way Toward Improving Health
Vitamin D was one of the nutrients most people failed to get sufficient amounts of, even when taking vitamin supplements. One reason for this is probably because vitamin D is best obtained from sensible sun exposure, not pills or fortified foods.
This is how your body was designed to produce it, and oral supplementation appears to have certain drawbacks. That said, vitamin D-rich foods and D3 supplements may be necessary if you cannot get adequate sun exposure year-round.
Avoiding processed foods is another important consideration, as they tend to be loaded with the herbicide glyphosate (used on most conventional and genetically engineered food crops), and glyphosate has been shown to interfere with enzymes responsible for activating vitamin D in your liver and kidneys.
A growing body of evidence shows that vitamin D plays a crucial role in maintaining optimal health. There are about 30,000 genes in your body and vitamin D affects nearly 3,000 of them, as well as vitamin D receptors located throughout your body.
Signs indicating you may have a vitamin D deficiency include being over the age of 50, having darker skin, obesity, achy bones, feeling blue, head sweating and poor immune function.
Your best bet is to get your vitamin D level tested twice a year. Based on the evaluation of healthy populations that get plenty of natural sun exposure, the optimal range for general health appears to be somewhere between 50 and 70 nanograms per milliliter (ng/ml).
The Importance of Magnesium
Magnesium is the fourth most abundant mineral in your body, and researchers have detected more than 3,750 magnesium-binding sites on human proteins13 reflecting how important this mineral is for optimal biological functioning. The fact that magnesium is the third most common deficiency hints at the potential that magnesium deficiency might be involved in any health problem you may be experiencing.
Without sufficient amounts of magnesium your body simply cannot function at its best. Insufficient cellular magnesium levels set the stage for deterioration of proper metabolic function that can lead to more significant health problems. For example, magnesium plays an important role in:
- Your body's detoxification processes
- Preventing headaches
- Managing cardiovascular health
- Reducing insulin resistance14,15,16 and metabolic syndrome17 if you're at high risk. The mechanism by which magnesium controls glucose and insulin homeostasis appears to involve two genes responsible for magnesium homeostasis.18 Magnesium is also required to activate tyrosine kinase, an enzyme that functions as an "on" or "off" switch in many cellular functions and is required for the proper function of your insulin receptors
Are You Getting Enough Magnesium?
Experts estimate up to 80 percent of us are deficient in magnesium. Since there's no easily available commercial lab test that will give you an accurate reading of your magnesium status, the best way to evaluate your status is by tracking your signs and symptoms. In her book, "The Magnesium Miracle," Dr. Carolyn Dean lists 100 factors that will help you decide whether or not you might be deficient.
You can also find a check list to go through every few weeks in her blog post, "Gauging Magnesium Deficiency Symptoms."19 This will help you gauge how much magnesium you need in order to resolve your deficiency symptoms, including headaches, muscle spasms and fatigue.20
Besides eating magnesium-rich foods (see chart above) and/or taking a magnesium supplement (my favorite is magnesium threonate), you can also improve your magnesium status by taking regular Epsom salt baths or foot baths, which allow the magnesium to be absorbed into your body through your skin. Magnesium oil (from magnesium chloride) can also be used for topical application and absorption.
Mind Your Sodium to Potassium Balance
Sodium and potassium are two other key nutrients that need to be in balance for optimal health. It's particularly important for heart health. In addition to getting too little potassium in their diet, most people also get too much sodium. If you eat mostly processed foods, you're virtually guaranteed to end up with this imbalance.
According to the American Heart Association (AHA), an excess of sodium in your body may cause you to retain water, putting an extra burden on your heart, blood vessels and kidneys. Past recommendations have assumed that in some people this may lead to high blood pressure.21 But, sodium is just one-half of the ratio needed to keep your body healthy. The second half of the equation is potassium.
The protective effects of potassium are associated with the actions of nitric oxide release, which increases the relaxation of your arterial system and maintains blood pressure.22
The separate roles of sodium and potassium, and their relationship to heart health, have been studied over the years. Researchers have also evaluated the relationship between a combination of sodium and potassium and heart health. One recent study showed the sodium-to-potassium ratio was more strongly associated with blood pressure maintenance than were either sodium or potassium individually.23
Other studies have also suggested that the ratio of sodium to potassium is one of the most important risk factors for managing normal cardiovascular function.24,25,26 Women who eat a higher amount of potassium-rich foods are able to better manage their normal cardiovascular function.27
Data from over 12,000 individuals participating in the 3rd National Health and Nutrition Examination also showed that higher sodium was associated with increased health risks, while a higher potassium level was also associated with increased risks.28
Potassium-Rich Foods Low in Sodium
The best way to balance your sodium and potassium ratio is to increase your intake of foods rich in potassium, while maintaining a moderate amount of sodium intake. Whole foods naturally high in potassium and low in sodium include:29,30
✓ White beans
✓ Sweet potatoes
✓ Cherry tomatoes
✓ Red grapefruit
✓ Lima beans
✓ Acorn squash
✓ Nuts and seeds
✓ Bee pollen
Vitamin E for Brain Health
Vitamin E is particularly important for brain health, so the fact that an estimated 81 percent of 2- to 8-year-olds, 98 percent of teenagers and 95 percent of adults are at risk for deficiency is disconcerting to say the least.31 Recent animal research warns that vitamin E deficiency may actually affect the brain, and studies have also found it may help delay the loss of cognitive function.32
Vitamin E also helps protect against free radical damage and the effects of aging. The term "vitamin E" refers to a family of at least eight fat-soluble antioxidant compounds, divided into two main categories: tocopherols (which are considered the "true" vitamin E) and tocotrienols, each of which has subfamilies of four different forms.
Your best source of intake is vitamin E-rich foods. When opting for a supplement, chose a full-spectrum vitamin E (meaning the broader family of mixed natural tocopherols and tocotrienols). Avoid the synthetic form. You can tell what you're buying by carefully reading the label. Natural vitamin E is always listed as the "d-" form (d-alpha-tocopherol, d-beta-tocopherol, etc.), while synthetic vitamin E is listed as "dl-" forms.
Vitamins A and D Work in Tandem
An estimated 57 percent of teens and 51 percent of American adults are at risk for insufficiency or deficiency of vitamin A, an essential fat-soluble vitamin important for maintaining healthy skin, teeth, bones, cell membranes, vision and healthy immune function.
Vitamins A and D work in tandem, and there's evidence suggesting that without vitamin D, vitamin A can be ineffective or even toxic. On the other hand, if you're deficient in vitamin A, vitamin D cannot function properly either, so a balance of these two vitamins is essential.
Unfortunately, we do not yet know the optimal ratios between these two vitamins. Moreover, both vitamin A and vitamin D production is tightly controlled in your body, and taking either of them in supplemental form ends up bypassing important controls that keep you from experiencing potential toxic effects. For these two reasons, it's best to get vitamins A and D from food and sun exposure, rather than relying on supplements.
The best source of vitamin A that your body can actually use are animal products such as grass-fed meat and poultry, liver, fish and raw organic dairy products like butter. These foods contain retinol, preformed vitamin A that your body can easily use.33 It can be very difficult to get sufficient amounts of vitamin A from beta-carotene (pre-vitamin A, found in plant foods like fruits and vegetables) alone.
Calcium Must Be Balanced With Vitamin D, Magnesium and K2
Calcium is one of several nutrients required for strong, healthy bones. However, it's important to not overdo it on calcium supplements, as it needs to be balanced with vitamins D, K2 and magnesium. Excessive amounts of calcium can end up causing more harm than good.
- Too much calcium and not enough magnesium typically causes muscle spasms, and in extreme cases can lead to a heart attack and sudden death.
- Too much calcium and not enough vitamin K2 will promote hardening of the arteries and softening of your bones. The reason for these effects is because the biological role of vitamin K2 is to remove calcium from areas where it shouldn't be (such as in your arteries and soft tissues), and shuttle it into the appropriate areas (such as your bones and teeth).
- Too much vitamin D and not enough vitamin K2 is what produces the symptoms of vitamin D toxicity, which includes inappropriate calcification of your arteries.
Ideal Sources of Vitamin K2, Silica and Calcium
One of the best ways to achieve a healthy balance between vitamin D, magnesium, K2 and calcium is to get plenty of sensible sun exposure and eat a diet rich in fresh whole foods. Good sources of calcium are raw milk from pasture-raised cows, leafy green vegetables and the pith of citrus fruits, carob and wheatgrass.
You also need sources of silica, which some researchers say is actually enzymatically "transmuted" by your body into the kind of calcium your bones can use. Good sources of silica are cucumbers, bell peppers, tomatoes and a number of herbs, including horsetail, nettles, oat straw, alfalfa and raw cacao, which is also extremely rich in highly bioavailable magnesium.
Vitamin K2 is only present in fermented foods, such as natto (a fermented soy product), fermented vegetables like sauerkraut, certain cheeses, raw butter and kefir made from raw milk. If you decide to use a supplement, menaquinone-7 (MK-7) is the kind of vitamin K2 you want to look for, as this form is extracted from real food.34
Tips to Supercharge Your Diet With Nutrients
As much as possible, I recommend getting the nutrients your body needs from whole foods. As shown above, many of the most common nutrient deficiencies can be traced back to a rather limited range of foods, specifically:
- Fatty fish
- Nuts and seeds
- Fruits and vegetables
Trading processed foods for real, whole foods, with a focus on these three categories, can go a long way toward correcting an array of nutritional imbalances and/or insufficiencies. Following are a few additional tips that can help boost your intake of the wide variety of nutrients your body needs:
- Homemade Bone Broth: Bone broth contains high amounts of calcium, magnesium and other nutrients.
- Sprouts: Sprouts can contain up to 100 times more enzymes than raw fruits and vegetables, allowing your body to extract more vitamins, minerals, amino acids and essential fats from the foods you eat.
- Juicing: Juicing not only helps you to consume more nutrient-rich veggies; it also helps you absorb the nutrients they contain. Juicing will help to "pre-digest" the veggies for you, so you will receive most of the nutrition, rather than having it go down the toilet.
- Fermented Foods: Fermented foods support the beneficial bacteria in your gut, which helps with mineral absorption and plays a role in producing nutrients such as B vitamins and vitamin K2, the latter of which is important for the proper functioning of other nutrients, such as calcium and vitamin D.