This vitamin deficiency test is a free, symptom-based quiz designed to help you assess your personal risk for common nutrient deficiencies including vitamin D, vitamin B12, iron, magnesium, zinc, and vitamin C. While no quiz can replace laboratory testing, research suggests that many adults live with undiagnosed deficiencies for months or years because symptoms such as fatigue, hair loss, and mood changes are easy to attribute to other causes.
For a broader look at which nutrients matter most for women, see our best vitamins for women: evidence-based guide. The World Health Organization estimates that micronutrient deficiencies affect over two billion people worldwide. By reviewing your symptoms systematically, this quiz can help you decide whether a conversation with your healthcare provider — and targeted blood work — is warranted.
Vitamin Deficiency Risk Quiz
Take our free quiz below.
Common Vitamin Deficiencies and Their Symptoms
S. adults according to research published in Nutrition Research. Symptoms associated with low vitamin D include bone pain, muscle weakness, fatigue, and low mood.
Vitamin B12 deficiency symptoms: a clinical overview covers the hallmark signs — fatigue, tingling or numbness in the extremities, and pallor from megaloblastic anemia — that are especially common in people over 50, vegans, and those taking long-term metformin or proton pump inhibitors.
Iron deficiency symptoms and when to get tested is another essential read: iron deficiency is the most common nutritional deficiency globally and presents with fatigue, hair loss, brittle nails, poor wound healing, and pale skin. Magnesium deficiency may manifest as muscle cramps, sleep disruption, and low mood, as magnesium plays a role in over 300 enzymatic reactions in the body.
Zinc and vitamin C deficiencies are associated with impaired immune function and slow wound healing. Because many of these symptoms overlap, laboratory testing is the only reliable way to identify which — if any — deficiency is present.
Who Is at Higher Risk for Nutrient Deficiency?
Certain groups face a meaningfully elevated risk of micronutrient deficiency. Women of reproductive age are at higher risk of iron deficiency due to menstrual blood loss; the NIH Office of Dietary Supplements notes that nearly 10% of American women aged 12–49 are iron deficient. Older adults absorb vitamin B12 less efficiently due to decreased stomach acid production, making deficiency common even with adequate dietary intake.
People who follow strict vegan or vegetarian diets are at elevated risk for B12, iron (non-heme iron is less bioavailable), zinc, and omega-3 fatty acid insufficiency. Individuals with limited sun exposure — including those living at northern latitudes, working indoors, or consistently using sunscreen — are at elevated risk for vitamin D deficiency.
People with gastrointestinal conditions such as celiac disease, Crohn's disease, or a history of bariatric surgery may have impaired nutrient absorption across multiple vitamins and minerals. Pregnant and breastfeeding individuals have substantially increased requirements for iron, folate, iodine, and vitamin D.
How to Test for Vitamin Deficiencies
The definitive method for identifying a vitamin or mineral deficiency is a blood test ordered by a healthcare provider. Standard tests for common deficiencies include: serum 25-hydroxyvitamin D for vitamin D status; serum B12 and methylmalonic acid (MMA) for B12 status; a complete blood count (CBC) with serum ferritin for iron status; and serum zinc for zinc adequacy.
Some comprehensive micronutrient panels test for a broad range of vitamins and minerals simultaneously, though these are not always covered by insurance and vary in clinical reliability. Mayo Clinic advises against beginning supplementation based on symptoms alone, because some conditions that mimic deficiency — such as hypothyroidism or chronic fatigue syndrome — require different treatment entirely.
If blood work confirms a deficiency, your provider can recommend an appropriate supplementation dose and timeline, and will typically retest to confirm correction.
Medical Disclaimer: This tool is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Results are estimates and should not replace guidance from a qualified healthcare provider. Always consult your doctor before making health decisions.
Frequently asked questions
What blood tests check for vitamin deficiencies?
Common laboratory tests for nutrient deficiencies include: serum 25-hydroxyvitamin D (vitamin D), serum cobalamin and methylmalonic acid (vitamin B12), complete blood count with serum ferritin and transferrin saturation (iron), serum zinc, serum magnesium, and plasma or serum vitamin C. A registered dietitian or physician can recommend which tests are appropriate based on your individual symptoms, dietary patterns, and medical history. Not all of these tests are included in standard annual bloodwork, so it may be necessary to specifically request them.
Can you tell if you have a vitamin deficiency just from symptoms?
Symptoms can suggest the possibility of a deficiency and help direct which tests to run, but they cannot confirm one. Most deficiency symptoms — fatigue, hair loss, low mood, and poor immune function — are non-specific, meaning they can be caused by many different conditions including thyroid disorders, sleep problems, anemia from non-nutritional causes, and depression. Only laboratory testing can definitively identify a deficiency and distinguish it from other causes. This quiz is designed to help you assess your symptom profile, not to provide a clinical diagnosis.
What are the most common vitamin deficiencies in women?
Research consistently identifies iron deficiency as the most common nutrient deficiency in women of reproductive age, largely due to menstrual blood loss. Vitamin D deficiency is extremely prevalent across all adult women, particularly those with limited sun exposure or darker skin tones. Magnesium inadequacy is also widespread in the general population. Women who are pregnant or breastfeeding have elevated requirements for iron, folate, iodine, and calcium that may be difficult to meet through diet alone, making prenatal supplementation a standard recommendation by organizations such as the American College of Obstetricians and Gynecologists.
Is it better to get vitamins from food or supplements?
Nutrition experts and public health organizations generally recommend obtaining vitamins and minerals primarily through food, which provides nutrients in forms the body recognizes and alongside cofactors that may aid absorption. However, food sources are not always sufficient — vitamin D is difficult to obtain in adequate amounts from diet alone for most people, and vitamin B12 from food requires intact stomach acid for absorption. The NIH Office of Dietary Supplements notes that supplements are appropriate and beneficial when a deficiency is confirmed or risk is high. High-dose supplements of fat-soluble vitamins (A, D, E, K) can accumulate to toxic levels, so supplementation beyond standard amounts should be guided by a healthcare provider.