Complete Vitamin and Mineral Deficiency Guide
Evidence-based guide to essential vitamins and minerals: deficiency symptoms, food sources, and recommended daily intake.
Medically reviewed by Dr. Sarah Johnson, RD, PhD
Published: December 1, 2025 | Last Updated: December 24, 2025
Vitamin D (Calciferol)
What It Does
Vitamin D helps your body absorb calcium, supports bone health, immune function, and mood regulation. It's often called the "sunshine vitamin" because your skin produces it when exposed to sunlight. Works synergistically with magnesium for optimal bone health.
Deficiency Symptoms
- Fatigue and tiredness
- Bone pain and muscle weakness
- Frequent infections
- Depression or mood changes
- Impaired wound healing
Food Sources
Fatty fish (salmon, mackerel, sardines), fortified milk and cereals, egg yolks, mushrooms exposed to UV light.
Recommended Daily Intake
Adults: 600-800 IU (15-20 mcg) | Seniors (70+): 800 IU (20 mcg)
Vitamin B12 (Cobalamin)
What It Does
Essential for red blood cell formation, DNA synthesis, and neurological function. Critical for energy production and brain health.
Deficiency Symptoms
- Extreme fatigue and weakness
- Tingling in hands and feet (neuropathy)
- Memory problems and confusion
- Pale or jaundiced skin
- Shortness of breath and dizziness
Food Sources
Meat, fish, poultry, eggs, dairy products, fortified cereals and nutritional yeast (for vegans).
Recommended Daily Intake
Adults: 2.4 mcg | Pregnant women: 2.6 mcg | Breastfeeding: 2.8 mcg
Iron
What It Does
Iron is crucial for making hemoglobin, the protein in red blood cells that carries oxygen throughout your body. It also supports immune function and cognitive development.
Deficiency Symptoms (Anemia)
- Extreme fatigue and weakness
- Pale skin, nails, and gums
- Shortness of breath
- Cold hands and feet
- Brittle nails and hair loss
- Unusual cravings (ice, dirt - called pica)
Food Sources
Heme Iron (better absorbed): Red meat, poultry, fish
Non-Heme Iron: Lentils, beans, spinach, fortified cereals, tofu
Tip: Pair non-heme iron with Vitamin C (citrus, tomatoes) to boost absorption. Avoid taking with calcium supplements as they can interfere with absorption.
Recommended Daily Intake
Men: 8 mg | Women (19-50): 18 mg | Pregnant women: 27 mg
Magnesium
What It Does
Involved in over 300 biochemical reactions. Supports muscle and nerve function, blood sugar control, blood pressure regulation, and bone health. Works with Vitamin D and calcium for optimal bone health.
Deficiency Symptoms
- Muscle cramps and spasms
- Fatigue and weakness
- Irregular heartbeat
- Numbness and tingling
- Anxiety and irritability
- Migraines
Food Sources
Dark leafy greens (spinach, kale), nuts and seeds (almonds, pumpkin seeds), whole grains, legumes, dark chocolate, avocados.
Recommended Daily Intake
Men: 400-420 mg | Women: 310-320 mg
Calcium
What It Does
Essential for building and maintaining strong bones and teeth. Also critical for muscle function, nerve transmission, and blood clotting. Requires Vitamin D for proper absorption.
Deficiency Symptoms
- Weak, brittle bones (osteoporosis)
- Muscle cramps and spasms
- Numbness in fingers and toes
- Abnormal heart rhythms
- Dental problems
Food Sources
Dairy products (milk, yogurt, cheese), fortified plant milks, sardines with bones, tofu, kale, broccoli.
Recommended Daily Intake
Adults (19-50): 1,000 mg | Women (51+) & Men (71+): 1,200 mg
Zinc
What It Does
Supports immune function, wound healing, DNA synthesis, and cell division. Important for taste and smell.
Deficiency Symptoms
- Weakened immune system (frequent infections)
- Hair loss
- Loss of appetite and taste
- Slow wound healing
- Skin rashes
Food Sources
Oysters, red meat, poultry, beans, nuts, whole grains, fortified cereals.
Recommended Daily Intake
Men: 11 mg | Women: 8 mg | Pregnant women: 11 mg
Vitamin C (Ascorbic Acid)
What It Does
Powerful antioxidant that supports immune function, collagen production (skin, tendons, ligaments), and helps absorb iron from plant-based foods. Enhances immune function when combined with zinc.
Deficiency Symptoms
- Frequent bruising
- Slow wound healing
- Bleeding gums and loose teeth
- Dry, rough skin
- Fatigue and weakness
- Scurvy (severe deficiency)
Food Sources
Citrus fruits (oranges, lemons), strawberries, bell peppers, broccoli, Brussels sprouts, tomatoes, kiwi.
Recommended Daily Intake
Men: 90 mg | Women: 75 mg | Smokers: +35 mg
Omega-3 Fatty Acids
What It Does
Essential fats crucial for brain health, heart health, and reducing inflammation. The three main types are ALA, EPA, and DHA.
Deficiency Symptoms
- Dry, flaky skin
- Brittle hair and nails
- Fatigue and poor concentration
- Joint pain and stiffness
- Depression and mood swings
Food Sources
EPA & DHA: Fatty fish (salmon, mackerel, sardines, anchovies)
ALA: Flaxseeds, chia seeds, walnuts, hemp seeds
Recommended Daily Intake
Combined EPA & DHA: 250-500 mg | ALA (Men): 1.6 g | ALA (Women): 1.1 g
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