As functional and integrative medicine practitioners, we spend a lot of time talking about nutrition to our patients. While this often involves the big three macronutrients -protein, fat and carbohydrates – we sometimes forget to emphasize the importance of their micronutrient cousins, which often can make a larger impact.
Micronutrients such as folate, zinc, magnesium, iodine, and our vitamins are essential in trace amounts for so many of the countless biochemical reactions that keep our body running, help us fight off infection, deal with oxidative stress and fuel our metabolism to mention a few. Despite our best efforts nutritionally, there are many reasons why we continue to be depleted in micronutrients, which I will highlight below.


Micronutrient Deficiency Can Occur in Developed Countries Too

The lack of certain micronutrients is sometimes thought of as more a ‘developing world problem’,  often associated with malnutrition and a calorie deficiency [1]. However, recent evidence suggests that developed countries, especially those struggling with high rates of obesity and overconsumption of empty calories may also be prone to micronutrient deficiency [2].

In fact, the lack of micronutrients could be fuelling the inflammatory processes contributing to chronic health conditions like chronic fatigue, insulin resistance, and thyroid dysfunction. While the NHANES study showed the prevalence of micronutrient deficiencies such as  vitamins A, B6, B12, C, D, E, and folate in the US population [3], we can see similar trends in Europe as well [4]. Is it because we are also increasingly adhering to a SAD (standard American diet) on this side of the Atlantic, or could some other reasons also be to blame?


What You Sow is What You Reap – The Sad State of our Soils

Starting on a more macro scale, one global issue that needs to be highlighted is the quality of our soils that are growing the micronutrient rich food, which can have a big impact on not only the taste of the food but the quality. Many of my older relatives complain about ‘tomatoes tasting better back in the day’, and it seems like this isn’t just nostalgia. A Kushi Institute analysis of nutrient data from 1975 to 1997 found that the average calcium levels in 12 fresh vegetables dropped 27 percent; iron levels 37 percent; vitamin A levels 21 percent, and vitamin C levels 30 percent [5]. Another study concluded that one would have to eat eight oranges today to derive the same amount of Vitamin A as our grandparents would have gotten from one [5]. Why is this the case?

One such reason is the state of the soil health in Europe. We rightfully recognize that healthy soil is essential for the health of our water and ecosystems. The quality of the soil plays a crucial role in regulating a number of life sustaining natural biological and chemical cycles. Recall that carbon, nitrogen, and a range of essential nutrients are continuously recycled between soil and plants, geological deposits, ground water and the atmosphere, but this process has been disrupted by current agricultural practices.

While boosting crop yields, modern intensive agricultural methods have stripped increasing amounts of nutrients from the soil in which the food we eat grows [6]. Recent articles have direly highlighted that the soil is being overexploited, degraded, and lost due to inappropriate land management practices and industrial activities in many parts of Europe [6]. This has led to soil sealing, contamination, erosion, soil acidification, and loss of organic carbon. We also know that climate change has worsened soil degradation and contributes to harmful topsoil erosion [7].

Unfortunately, as the soil gets more nutrient depleted, so do we, as these processes are all intertwined. While we thankfully are seeing more and more initiatives in Europe to promote organic farming, use permaculture etc. that could offset these issues, I still point out the need to supplement certain micronutrients (often zinc & magnesium) in addition to buying small-scale, organically-grown produce when discussing food plans with my patients.

Are Other Factors Compounding the Issue?

Micronutrient depletion does not only have to come from our diet. An often overlooked and less discussed cause could be the side effects of certain pharmaceutical medications. We know that many of these medications are usually designed to switch off or modify certain enzymes in our bodies. By interfering with  our natural mechanisms, these medications can often temporarily provide symptomatic relief, but can use up our micronutrient supply [8].

Some notable examples include proton pump inhibitors, which by stopping our production of HCl/stomach acid, can deplete our calcium, folic acid, iron and vitamin B12 & D supplies;  ACE inhibitors, which could contribute to lower levels of zinc; and statins, which can deplete our fat soluble vitamins, such as E, D & K [9].

In my practice, when I have looked up side effects of many groups of medications, symptoms such as fatigue and malaise are listed as “common’” This might be because of the essential nutrients depleted when taking such medications. For patients taking such medications, supplementation with micronutrients can not only offset their shortfall, but also allow him or her to continue taking their medicines more safely. For example, antidepressants may not provide their full effect if folate is not supplemented. I often like to refer to this table provided by the AAFP for more examples [9].



A Personal Approach to a Common Problem

In functional and integrative medicine, which we know takes a very personalized view of patients and their story and symptoms, we often question what the exact RDA (required daily amount) of a micronutrient should be. I would personally argue that based on a person’s genetics, SNP profiles and symptoms, supplementation dosage often needs to surpass the RDA to yield desired effects.

A study by Bruce Ames, one of the original forefathers of functional medicine, showed that by administrating higher doses of cofactors like zinc and magnesium, one could overcome genetic variants of suboptimal enzyme function [10].

As lab tests evaluating one’s DNA and SNPs become more popular, patients are becoming more aware of their potentially deficient enzymes. Supplementing with micronutrients can be a simple and effective way to bypass these deficiencies. For example, patients struggling with heavy metal toxicity, processing prescribed hormones or pharmaceutical drugs, or pursuing general detoxification may also require higher doses of cofactors like vitamins B2, B3, B6, B12, folic acid, zinc and magnesium [11]. Other micronutrients such as magnesium, chromium, zinc, and selenium, are also needed to modify insulin responsiveness at the cellular level, and be beneficial for those with diabetes.

Also, I also tend to recommend that patients with thyroid dysfunction supplement with cofactors needed for a healthy functioning thyroid, which include selenium, iron, and vitamin A [12,13].

When it comes to choosing particular products, I think it is important to work with brands who are close to practitioners and specialists and who understand our patients’ needs. Quality always goes before quantity, and I’d rather advise taking a high-quality supplement than multiple discount versions.


Dr. Miriam Mikicki is a Medical Doctor & General Practitioner practicing functional & integrative medicine. She helps patients find the root causes of their health issues, serving them locally in London and internationally through telemedicine consultations from her practice, Mikicki Medical. Dr Mikicki is a proud member of the Institute for Functional Medicine.


Disclaimer: The contents of this article are for information purposes only and do not constitute medical advice. Please consult your qualified healthcare professional to obtain advice suitable to your personal circumstances.


[1]   World Health Organization. Micronutrient deficiencies. World Health Organization. Published 2019. Accessed 7 September 2020.

[2]   Bird JK, Murphy RA, Ciappio ED, Mcburney MI. Risk of Deficiency in Multiple Concurrent Micronutrients in Children and Adults in the United States. Nutrients. 2017;9(7). doi:10.3390/nu9070655. PMID:28672791

[3]   U.S. Department of Agriculture, Agricultural Research Service. 2014. Total Nutrient Intakes: Percent Reporting and Mean Amounts of Selected Vitamins and Minerals from Food and Beverages and Dietary Supplements, by Gender and Age, What We Eat in America, NHANES 2011-2012. Available:

[4]   Kaganov B, Caroli M, Mazur A, Singhal A, Vania A. Suboptimal Micronutrient Intake among Children in Europe. Nutrients. 2015;7(5):3524-35. doi:10.3390/nu7053524. PMID:25894741.

[5]   Scientific American. Dirt Poor: Have Fruits and Vegetables Become Less Nutritious? Published 27 April 2011. Accessed 7 September 2020.

[6]   Jones A, Panagos P, Barcelo S et al. The State of Soil in Europe – A Contribution of the JRC to the European Environment Agency’s Environment and Outlook Report – SOER 2010. Luxemburg: Publications Office of the European Union; 2012. doi:10.3390/nu7053524.

[7]   de Haes HA, Voortman RL, Bastein T et al. Scarcity of micronutrients in soil, feed, food, and mineral reserves – Urgency and policy options. Culemborg: Platform Agriculture, Innovation and Society; 2012. Accessed 7 September 2020.

[8]   Mohn ES, Kern HJ, Saltzman E, Mitmesser SH, Mckay DL. Evidence of Drug-Nutrient Interactions with Chronic Use of Commonly Prescribed Medications: An Update. Pharmaceutics. 2018;10(1). doi:10.3390/pharmaceutics10010036. PMID:29558445.

[9]   Pharmavite LLC. Common Drug Classes, Drug-Nutrient Depletions, & Drug-Nutrient Interactions. Published 2017. Accessed 7 September 2020 2020.

[10] Ames BN. Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage. Proc Natl Acad Sci USA. 2006;103(47):17589-94. doi:10.1073/pnas.0608757103. PMID:17101959.

[11] Vance TM, Chun OK. Zinc Intake Is Associated with Lower Cadmium Burden in U.S. Adults. J Nutr. 2015;145(12):2741-8. doi:10.1073/pnas.0608757103. PMID:26491124.

[12] Zimmermann MB, Köhrle J. The impact of iron and selenium deficiencies on iodine and thyroid metabolism: biochemistry and relevance to public health. Thyroid. 2002;12(10):867-78. doi:10.1089/105072502761016494. PMID:12487769.

[13] Contempré B, Duale NL, Dumont JE, Ngo B, Diplock AT, Vanderpas J. Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. Clin Endocrinol (Oxf). 1992;36(6):579-83. doi: 10.1111/j.1365-2265.1992.tb02268.x. PMID:1424183.