Common Nutrient
Deficiencies

Nutrient deficiencies are more widespread than most people realise — several affect a large portion of the population and go undiagnosed for years. This section covers the most prevalent ones with evidence on identification, food sources and supplementation.

BillionsPeople affected globally by vitamin D deficiency alone
~10–30%Estimated magnesium deficiency prevalence in Western populations
Section under development

We are building dedicated articles on each major deficiency. In the meantime, our Supplement Facts library covers the clinical details for most of the nutrients listed below — including dosage, risk groups and evidence on supplementation.

Most Common Deficiencies — Overview

The table below lists the nutrient deficiencies we will be covering in detail. Where a full Supplement Facts review already exists, we link to it directly.

Nutrient Populations Most at Risk Common Symptoms Article
Vitamin D Northern latitudes, dark skin, elderly, limited sun exposure Fatigue, bone pain, immune suppression, low mood Live
Magnesium High-stress individuals, athletes, poor diet Muscle cramps, poor sleep, anxiety, fatigue Live
Iron Women (reproductive age), vegetarians, endurance athletes Fatigue, shortness of breath, poor concentration Live
Vitamin B12 Vegans, vegetarians, elderly, people on metformin Nerve damage, fatigue, cognitive decline, anaemia Live
Folate (B9) Pregnant women, people with MTHFR variants, alcohol use Anaemia, neural tube defects, fatigue, mouth sores Live
Zinc Vegetarians, elderly, people with GI conditions Immune dysfunction, slow wound healing, taste/smell loss Live
Selenium Low-selenium soil regions, thyroid conditions Thyroid dysfunction, immune suppression, muscle weakness Live
Calcium Dairy-free diets, post-menopausal women Bone density loss, muscle cramps, dental issues Live