
Nutritional deficiencies - What are the most common vitamin and nutrient deficiencies?

Written By:
Katie Stone - Naturopath
Medical Reviewer:
Dr. Nare Simonyan - PhD Pharmaceutical Science
Edited By:
Kari Asadorian - Bachelor of Science in NursingUpdated On:
June 18, 2025What are the most common nutritional deficiencies?
Vitamin and mineral deficiencies affect around a third1 of the world’s population. Although these deficiencies are more prevalent in developing countries, they are becoming more common in developed countries.
Nutritional deficiencies can occur for several reasons, including:
- poor diet or dietary insufficiency
- poor absorption of macro- or micronutrients due to gastrointestinal disorders such as Crohn's, celiac disease, or surgical procedures.
- increased loss of nutrients from the body
- increased energy expenditure
- poor nutritional content of food due to modern farming practices and food storage/manufacturing
Low intake of fruits, vegetables, lean protein, and grains can substantially affect nutritional status. However, it is also important to note that even these foods may not provide adequate nutrients due to modern methods of growing and processing.2 Malabsorption of certain nutrients can also affect nutritional status.3 Taking multivitamins can help to restore deficiencies, maintain nutrient levels, and support overall good health.
Most common vitamin and mineral deficiencies
Vitamin B12
B12 deficiency has been described as “a major public health problem worldwide”. It affects an estimated 6% of adults aged under 60 years, but around 20% of those older than 60.4
B12 deficiency may result from a lack of B12 foods in the diet, especially in the case of vegans or vegetarians.
Malabsorption disorders or surgical history can also affect the ability to obtain vitamin B12 from food, as well as certain medications (such as acid-suppressing agents and metformin).
The MTHFR genetic mutation5 is also associated with a higher risk of B12 deficiency.
Methyl-Life’s® Active B12 Complete contains three naturally-occurring forms of B12 shown in clinical studies to improve vitamin B12 status.6 These forms are bioidentical to the B12 found in the human body and vastly superior to cyanocobalamin, a synthetic form of B12 that occurs only in trace amounts in the body.7
Magnesium
An estimated up to 50% of the US population l does not meet daily magnesium requirements.8
Magnesium is essential for over 300 biochemical reactions in the body and plays a crucial role in the cardiovascular, neuromuscular, and nervous system. Low magnesium levels can lead to cardiovascular and metabolic diseases, skeletal disorders, respiratory illness, and neurological disorders (stress, depression, and anxiety).9
The most effective way to restore magnesium levels is via supplementation with a highly bioavailable form of magnesium. Methyl-Life Sucrosomial® Magnesium is a highly bioavailable magnesium complex providing 32% elemental magnesium. Using an innovative delivery system that encapsulates the active ingredient within a phospholipid membrane, it delivers 320 mg of elemental magnesium directly into the bloodstream.
Vitamin D
Vitamin D deficiency is now more prevalent than ever, affecting approximately 1 billion people worldwide, while around 50% of vitamin D in the body remains stored and inactive. This is largely due to decreased dietary intake, decreased absorption, or decreased sun exposure.10
Vitamin D is essential for normal bone development and maintenance, immune function, nervous system maintenance. Studies show an association between vitamin D deficiency and cardiovascular disease, diabetes, depression, autoimmune diseases, and some cancers.11
Iron
Worldwide, the most common nutrient deficiency is iron. It is mainly caused by inadequate dietary intake, hemorrhage, and malabsorption. Iron deficiency typically affects children, women and the elderly, and those with medical conditions. Low iron levels typically lead to generalized weakness, fatigue, poor concentration, irritability, headaches, shortness of breath on exertion, and low energy.12
Folic Acid
Folate is another common nutrient deficiency. This B vitamin plays a critical role in fetal development and low folate levels are associated with numerous birth defects.13 Folate is also essential for healthy cardiovascular function, neurotransmitter production, DNA repair, and many other biological processes in the body. Chronic folate deficiency can result from dietary insufficiency and MTHFR mutations in which folic acid cannot be metabolized by the body.
Methyl-Life® specializes in methylfolate supplements made with only the purest and most stable form of calcium-based crystalline methylfolate. Using this biologically activated form of folate - the only form that can cross the blood-brain barrier - ensures maximum absorption and bioavailability.14 It is also the only form that can bypass the MTHFR genetic mutation. Methyl-life’s® methylfolate range includes dosages of 2.5 mg, 3 mg, 5 mg, 7.5 mg, 10 mg, and 15 mg to suit every health condition and life stage.
How to prevent nutritional deficiencies
1. Testing
If you have nutrient deficiency symptoms, a lab test can help to determine your nutritional status. However, it is important to note that lab tests may not provide an accurate picture of certain nutrient levels. For example, testing for B12 may result in false normal or even false high despite a deficiency due to high amounts of anti-intrinsic factor antibodies (proteins associated with pernicious anemia) in the serum.15
2. Evaluate your diet
Eating fresh, wholefoods (organic if possible) such as fruits, vegetables, lean protein, and grains is essential. These foods contain the natural vitamins, minerals, and antioxidants that your body needs to function. Avoid foods high in refined sugar, trans fats, artificial additives and/or have been processed/chemically refined, as these foods trigger inflammation and other negative health outcomes.
Seek help from a nutritionist if you have special dietary needs or you have obvious signs of nutrient deficiency.
3. Take supplements
Supplements can help to fill in the nutritional gaps in a diet. This is particularly vital for those who cannot absorb certain nutrients from food due to malabsorption disorders or genetic mutations (such as MTHFR). Supplements offer a source of specific vitamins and minerals in highly concentrated and bioavailable forms, allowing for optimal absorption and utilization in the body.
Methyl-Life’s® Chewable Methylated Multivitamin contains essential bioactive vitamins, patented minerals, antioxidants, and specific nutrients to support energy, cognition, immune function, and healthy homocysteine levels. It is ideal for those with MTHFR mutations, vegans, vegetarians, and those who are pregnant or breastfeeding*.

References
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Mandelbaum-Schmid, Judith; "Vitamin and mineral deficiencies harm one-third of the world's population, says new report."; Bulletin of the World Health Organization, 82 (3), 230 - 231. World Health Organization; (2004
https://apps.who.int/iris/handle/10665/269102
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Scientific American; "Dirt Poor: Have Fruits and Vegetables Become Less Nutritious?"; scientificamerican.com; 2011 Apr
https://www.scientificamerican.com/article/soil-depletion-and-nutrition-loss/
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Tyesha Zuvarox, Chris Belletieri; "Malabsorption Syndromes"; StatPearls [Internet]; 2023 Jul
https://www.ncbi.nlm.nih.gov/books/NBK553106/
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Alesia Hunt, Dominic Harrington, Susan Robinson; "Vitamin B12 deficiency"; BMJ: British medical journal; 2014 Sep
https://pubmed.ncbi.nlm.nih.gov/25189324/?dopt=Abstract
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E Zittan, M Preis, I Asmir, A Cassel, N Lindenfeld, S Alroy, D A Halon, B S Lewis, A Shiran, J E Schliamser, M Y Flugelman; "E Zittan 1, M Preis, I Asmir, A Cassel, N Lindenfeld, S Alroy, D A Halon, B S Lewis, A Shiran, J E Schliamser, M Y Flugelman; "High frequency of vitamin B12 deficiency in asymptomatic individuals homozygous to MTHFR C677T mutation is associated with endothelial dysfunction and homocysteinemia"; American journal of physiology. Heart and circulatory physiology; 2007 Jul
https://pubmed.ncbi.nlm.nih.gov/17449548/
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Cristiana Paul, David M Brady; "Comparative Bioavailability and Utilization of Particular Forms of B12 Supplements With Potential to Mitigate B12-related Genetic Polymorphisms"; Integrative medicine; 2017 Feb
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5312744/
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Cristiana Paul, David M Brady; "Comparative Bioavailability and Utilization of Particular Forms of B12 Supplements With Potential to Mitigate B12-related Genetic Polymorphisms"; Integrative medicine; 2017 Feb
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5312744/
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American Osteopathic Association; "Low magnesium levels make vitamin D ineffective." ScienceDaily;2018 Feb
https://www.sciencedaily.com/releases/2018/02/180226122548.htm
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A A A Ismail, Y Ismail, A A Ismail; "Chronic magnesium deficiency and human disease; time for reappraisal?"; QJM: An International Journal of Medicine, Volume 111, Issue 11; 2018 Nov
https://academic.oup.com/qjmed/article/111/11/759/4209351
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Mahbubul H. Siddiqee, Badhan Bhattacharjee, Umme Ruman Siddiqi; Mohammad MeshbahurRahman; "High prevalence of vitamin D deficiency among the South Asian adults: a systematic review and meta-analysis"; BMC Public Health; 2021 Oct
https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-021-11888-1
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Jasleen Kaur; Swapnil Khare; Omeed Sizar; Amy Givler; "Vitamin D Deficiency"; StatPearls [Internet]; 2025 Feb
https://www.ncbi.nlm.nih.gov/books/NBK532266/
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Nazma Hanif, Faiz Anwer; "Chronic Iron Deficiency"; StatPearls [Internet]; 2023 Aug
https://www.ncbi.nlm.nih.gov/books/NBK560876/
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Meera Viswanathan, Katherine A. Treiman, Julia Kish-Doto; "Folic Acid Supplementation for the Prevention of Neural Tube Defects An Updated Evidence Report and Systematic Review for the US Preventive Services Task Force"; JAMA; 2017 Jul
https://jamanetwork.com/journals/jama/fullarticle/2596299
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Rubens Pitliuk, Tatyanny Paula Pinto da Costa Santos Fucci; "L-methylfolate, a new option in psychiatric treatment, would it be linked to psoriasis relapse?"; Einstein / Instituto de Ensino e Pesquisa Albert Einstein; 2020 Nov
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687916/
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Utku Iltar, Mesut Göçer, Erdal Kurtoğlu; "False elevations of vitamin B12 levels due to assay errors in a patient with pernicious anemia"; Blood research; 2019 Jun
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6614102

About the Author
Katie is a qualified Naturopath (BNatMed) and freelance writer from New Zealand. She specializes in all things health and wellness, particularly dietary supplements and nutrition. Katie is also a dedicated runner and has completed more half-marathons than she can count!
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