Here are 10 well-documented nutritional deficiency diseases: scurvy (vitamin C), rickets (vitamin D), beriberi (vitamin B1), pellagra (vitamin B3), goiter (iodine), iron-deficiency anemia (iron), night blindness or xerophthalmia (vitamin A), kwashiorkor (protein), osteomalacia (vitamin D/calcium), and pernicious anemia (vitamin B12). Each develops when the body goes without a specific nutrient for long enough that normal function starts to break down.
This list is meant as a quick-reference guide, not a diagnostic tool. If you want the fuller picture on causes, symptom progression, and prevention strategies for each condition, our companion piece on nutritional deficiency diseases goes deeper into every one of these. Here, we’re keeping it short: one nutrient, one or two symptoms, one food source, entry after entry.
What counts as a nutritional deficiency disease?
A nutritional deficiency disease is a specific, recognizable illness that results from prolonged inadequate intake (or poor absorption) of a vitamin, mineral, or macronutrient. These aren’t vague states of “eating poorly” — they’re conditions with defined clinical presentations that clinicians have documented for centuries, some going back to sailors on long voyages (scurvy) or populations reliant on a single staple crop (pellagra, beriberi).
Most of these are rare in people with consistent access to varied food in higher-income countries today, but they still show up — in restrictive diets, certain medical conditions that impair absorption, pregnancy, older adults, and regions where nutritional deficiency remains widespread due to food insecurity. The World Health Organization continues to track several of these, particularly iodine, iron, and vitamin A deficiencies, as global public health priorities.
What are the 10 nutritional deficiency diseases to know?
1. Scurvy — Vitamin C deficiency
Scurvy develops when vitamin C intake drops low enough, for long enough, that the body can’t produce enough collagen to maintain connective tissue. Classic signs include bleeding, swollen gums, easy bruising, joint pain, and slow wound healing. It’s rare today but still turns up in people with very restricted diets or malabsorption issues. Food source: citrus fruits like oranges and grapefruit, plus bell peppers and strawberries.
2. Rickets — Vitamin D deficiency
Rickets affects growing bones in children, causing soft, weakened bones that can bow or bend under normal weight-bearing stress. It’s driven by insufficient vitamin D, often compounded by low calcium or phosphorus, and shows up as delayed growth, bone pain, and skeletal deformities like bowed legs. Food source: fatty fish such as salmon, egg yolks, and fortified milk.
3. Beriberi — Vitamin B1 (thiamine) deficiency
Beriberi comes in two forms. “Dry” beriberi damages peripheral nerves, causing tingling, numbness, and muscle weakness in the limbs. “Wet” beriberi affects the cardiovascular system, leading to swelling, shortness of breath, and in severe cases heart failure, according to the Cleveland Clinic. It was historically common in populations eating heavily milled white rice. Food source: whole grains, pork, and legumes.
4. Pellagra — Vitamin B3 (niacin) deficiency
Pellagra is classically remembered by “the three Ds”: dermatitis, diarrhea, and dementia. It causes a distinctive skin rash on sun-exposed areas, digestive upset, and in advanced stages, confusion or cognitive decline. Historically tied to diets centered on untreated corn, since the niacin in corn isn’t easily absorbed without processing. Food source: poultry, fish, peanuts, and enriched grains.
5. Goiter — Iodine deficiency
Goiter is a visible enlargement of the thyroid gland, which swells as it works overtime trying to produce thyroid hormone without enough iodine to do it. Symptoms include a noticeable neck swelling, and in some cases, difficulty swallowing or breathing as it enlarges. Iodine deficiency remains a leading cause of preventable thyroid disorders worldwide. Food source: iodized salt, seaweed, and dairy products.
6. Iron-deficiency anemia — Iron deficiency
This is the most common nutritional deficiency worldwide. Without enough iron, the body can’t make adequate hemoglobin, leaving red blood cells unable to carry oxygen efficiently. That shows up as persistent fatigue, pale skin, and shortness of breath during ordinary activity. It’s especially common in menstruating women, pregnant people, and young children. Food source: red meat, lentils, and spinach — see our guide on nutritional anemia for more.
7. Night blindness (xerophthalmia) — Vitamin A deficiency
Vitamin A deficiency impairs the retina’s ability to adjust to low light, causing difficulty seeing at dusk or in dim rooms — night blindness. Left untreated, it can progress to xerophthalmia, a drying of the cornea that can lead to permanent vision loss. The WHO identifies this as a leading preventable cause of childhood blindness in low-income regions. Food source: carrots, sweet potatoes, and liver.
8. Kwashiorkor — Protein deficiency
Kwashiorkor is a form of severe malnutrition driven primarily by inadequate protein intake, even when total calorie intake is somewhat maintained. According to the Cleveland Clinic, it’s most common in children ages 3 to 5 and produces a telltale swollen, fluid-retaining belly, along with thinning hair and skin changes. It often appears when a child is weaned onto a diet heavy in starch but light on protein. Food source: eggs, beans, fish, and dairy.
9. Osteomalacia — Vitamin D and calcium deficiency
Osteomalacia is essentially the adult counterpart to rickets — bones stay soft and weak because there isn’t enough vitamin D to help the body absorb calcium properly. Instead of the growth deformities seen in children, adults experience diffuse bone pain, muscle weakness, and a higher risk of fractures from minor falls. Food source: fortified milk, fatty fish, and moderate sun exposure — see our calcium nutrition guide for daily targets.
10. Pernicious (megaloblastic) anemia — Vitamin B12 deficiency
This anemia develops when the body can’t absorb or get enough vitamin B12 to produce healthy, normally-sized red blood cells. It causes fatigue, weakness, and in more advanced cases, nerve symptoms like tingling in the hands and feet or balance problems. It’s especially relevant for older adults and people following strict plant-based diets without supplementation. Food source: meat, eggs, dairy, and fortified nutritional yeast.
Which nutrients cause the most cases worldwide?
Iron, vitamin A, and iodine deficiencies are consistently flagged by the WHO as the three micronutrient shortfalls with the greatest global public health impact, largely because they affect the most people and carry serious consequences for maternal and child health. Iron-deficiency anemia alone affects a substantial share of women and children globally. Vitamin D and B12 gaps, meanwhile, are more common in higher-income countries due to limited sun exposure, aging populations, and increasingly restrictive diets.
Knowing which deficiencies are most prevalent doesn’t mean you should assume you have one. It just helps explain why iron panels, vitamin D labs, and B12 checks are among the most commonly ordered nutrient tests by primary care providers.
How can you tell if a symptom points to a deficiency?
Most of the diseases above take weeks to months of inadequate intake to fully develop, and early signs are often subtle — fatigue, mild skin or gum changes, or brain fog that’s easy to attribute to stress or poor sleep. That overlap is exactly why self-diagnosing from a symptom list is risky: fatigue alone could point to a dozen different issues that have nothing to do with nutrition.
The more reliable path is bloodwork. A basic metabolic panel plus targeted tests (ferritin, vitamin D, B12, or a full vitamin nutrition panel) can confirm or rule out a deficiency far more precisely than symptom-matching ever will.
How are these conditions typically addressed?
Once identified, most nutritional deficiency diseases respond well to correcting the underlying gap — through diet changes, supplementation, or both, under a clinician’s guidance. Severity determines the approach: mild cases often resolve with food-based changes over several weeks, while more advanced deficiencies may need supervised, higher-dose supplementation before diet alone can maintain healthy levels.
This is also where individual variation matters. Absorption issues, medications, pregnancy, and existing health conditions all change how much of a nutrient someone actually needs, which is why blanket “just take a multivitamin” advice often falls short of addressing a confirmed deficiency.
How can these deficiencies generally be prevented?
A varied diet that includes fruits, vegetables, whole grains, protein sources, and dairy or fortified alternatives covers most bases for most people. A few practical anchors:
- Include a vitamin C source (citrus, peppers, berries) with meals to also support iron absorption.
- Get regular, safe sun exposure or a food/supplement source of vitamin D, especially in winter months or northern latitudes.
- Use iodized salt where available, and include seafood or dairy periodically.
- Prioritize protein at each meal, not just at dinner, particularly for growing children and older adults.
- Consider a periodic omega-3 and micronutrient review if you follow a restrictive diet (vegan, low-FODMAP, or elimination-based).
None of this replaces individualized guidance — someone with a diagnosed absorption disorder or a restrictive diet for medical reasons needs a different plan than a generally healthy adult eating a varied diet.
FAQ: Nutritional Deficiency Diseases
What is the most common nutritional deficiency disease worldwide?
Iron-deficiency anemia is generally considered the most widespread, affecting a significant share of women, young children, and people with limited access to iron-rich foods globally. It’s also one of the easiest to test for and address once identified through routine bloodwork.
Can nutritional deficiency diseases be reversed?
Many respond well to correcting the nutrient gap, especially when caught early — through diet, supplementation, or both. Severity and duration matter: some effects, like certain bone or nerve changes from long-term deficiency, may only partially improve, which is why professional evaluation matters.
Do I need a blood test to confirm a deficiency?
Yes, generally. Symptoms like fatigue or brain fog overlap across many conditions unrelated to nutrition, so bloodwork (ferritin, vitamin D, B12, or a broader panel) is the most reliable way to confirm what’s actually low before changing your diet or starting supplements.
Are these diseases still a concern in developed countries?
Less common in their severe historical forms, but milder versions of vitamin D, B12, and iron deficiency remain fairly common, particularly among older adults, pregnant people, and those on restrictive diets. Mild cases are often missed because symptoms are subtle.
Is it safe to just take a multivitamin as prevention?
A multivitamin can help fill small gaps, but it’s not a substitute for addressing a confirmed deficiency, which often needs a targeted, higher dose of a specific nutrient. It’s best to test first and supplement based on actual results rather than guessing.
If any of this sounds like it might apply to you — persistent fatigue, unusual symptoms, or a restrictive diet you’re not sure is meeting your needs — the right next step is getting your levels checked rather than guessing from a list. An online nutritionist consultation can help you figure out what’s actually going on and build a plan around it.
