Vitamin and Mineral Deficiency Symptoms: The Complete Chart
July 21, 2026 · 8 min read
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The four most common deficiencies are vitamin D, iron, B12, and magnesium — and their symptoms overlap heavily (fatigue, weakness, low mood). Use the chart below to narrow down suspects, then confirm with a blood test before supplementing: treating the wrong deficiency wastes months, and some (like B12) cause permanent nerve damage when missed.
The deficiency symptoms chart
| Nutrient | Common deficiency signs | Most at risk |
|---|---|---|
| Vitamin D | Fatigue, bone and lower-back pain, muscle weakness, low mood, frequent infections | Limited sun exposure, darker skin, adults 65+, obesity, malabsorption |
| Iron | Exhaustion, pale skin, shortness of breath, cold hands and feet, brittle nails, cravings for ice | Menstruating and pregnant people, vegans and vegetarians, frequent blood donors |
| Vitamin B12 | Fatigue, tingling or numbness in hands and feet, memory problems, sore tongue, pallor | Adults 60+, vegans, people on metformin or acid reducers, post-gastric surgery |
| Magnesium | Muscle cramps and twitches, poor sleep, irritability, headaches, heart palpitations | High alcohol intake, type 2 diabetes, GI disease, diets low in greens, nuts, seeds |
| Folate (B9) | Fatigue, mouth sores, irritability, anemia; critical in early pregnancy | Pregnancy, heavy alcohol use, malabsorption, certain medications |
| Vitamin C | Easy bruising, bleeding gums, slow wound healing, rough bumpy skin, joint pain | Very low fruit/vegetable intake, smokers |
| Zinc | Frequent infections, loss of taste or smell, slow healing, hair loss, skin problems | Vegetarians, pregnancy, GI disorders, heavy alcohol use |
| Calcium | Usually silent until bone loss; muscle cramps, numbness, brittle nails in severe cases | Low dairy intake, lactose intolerance, postmenopausal women, vitamin D deficiency |
| Vitamin A | Poor night vision, dry eyes, dry skin, frequent infections | Rare in developed countries; fat-malabsorption conditions |
| Iodine | Enlarged thyroid (goiter), fatigue, weight gain, feeling cold | People avoiding iodized salt, dairy, and seafood; pregnancy |
The big four, in more detail
Vitamin D — the most common deficiency
Roughly a billion people worldwide have low vitamin D. Symptoms are vague — tiredness, aches, low mood — so it usually goes unnoticed until a 25(OH)D blood test. Levels below 20 ng/mL (50 nmol/L) are considered inadequate.
Iron — the most common cause of anemia
Iron deficiency progresses from depleted stores (low ferritin) to full anemia. The giveaway combination is exhaustion plus pale skin plus breathlessness on stairs. Confirm with ferritin and a complete blood count — and don't supplement iron "just in case": excess iron is harmful, and unexplained deficiency needs a cause investigated.
Vitamin B12 — the one you can't afford to miss
B12 deficiency causes anemia and nerve damage — tingling, numbness, balance and memory problems — which can become permanent if untreated. About 20% of adults over 60 are deficient, often from reduced absorption rather than diet. Vegans need a supplement or fortified foods, full stop.
Magnesium — the quiet one
Magnesium is involved in over 300 enzyme reactions, and most people in Western countries eat less than recommended. Classic signs are muscle cramps, eye twitches, poor sleep, and irritability. Standard blood tests miss it easily because less than 1% of body magnesium is in serum — diet history and symptoms matter as much as the lab number.
When to get tested
- Persistent fatigue that sleep doesn't fix
- You belong to a risk group in the chart above
- You follow a restricted diet (vegan, very low calorie, elimination diets)
- You take medications that affect absorption (metformin, PPIs, diuretics)
- Before starting high-dose supplements — get a baseline so you can measure progress
Vitamin Tracker keeps your lab results and supplement routine side by side, so you can see whether your levels actually improve.
Frequently asked questions
What are the most common vitamin deficiencies?
Vitamin D, iron, vitamin B12, and magnesium are the most common nutrient deficiencies worldwide. Vitamin D deficiency affects roughly a billion people, and the NIH estimates about 20% of adults over 60 are B12-deficient.
How do I know which vitamin I'm deficient in?
Symptoms overlap too much to guess reliably — fatigue alone can point to vitamin D, iron, B12, or magnesium. The only dependable way is a blood test ordered by your doctor, guided by your symptoms, diet, and risk factors.
Can a blood test detect all vitamin deficiencies?
Common ones, yes: 25(OH)D for vitamin D, ferritin and a CBC for iron, serum B12, and red-blood-cell folate are all standard. Some nutrients, like magnesium, are harder to assess because blood levels don't reflect body stores well.
How long does it take to fix a vitamin deficiency?
It varies by nutrient and severity. B12 and vitamin D levels typically improve within 6–12 weeks of consistent supplementation; refilling iron stores often takes 3–6 months. Retesting after about 3 months is a common recommendation.
Sources
- Cleveland Clinic — Vitamin Deficiency
- NIH ODS — Vitamin B12 Fact Sheet for Health Professionals
- NIH ODS — Magnesium Fact Sheet for Health Professionals
- NIH ODS — Iron Fact Sheet for Health Professionals
This article is for informational purposes only and is not medical advice. Vitamin Tracker is a tracking and organization tool, not a medical device. Always talk to a qualified clinician before starting, stopping, or changing supplements — especially if you are pregnant, take prescription medication, or have a health condition.