The Nutrients Most Vegans Are Missing (And How to Fix It)
A registered dietitian breaks down the 6 nutrients vegans are most likely to be deficient in — with practical, affordable solutions for each.
Let me start with this: a well-planned vegan diet can be incredibly healthy. Research consistently shows benefits for heart health, certain cancers, and longevity.
But "well-planned" is doing heavy lifting in that sentence.
The reality is that most vegans I work with have at least one nutrient gap they don't know about — not because veganism is flawed, but because nobody told them what to watch for. Here are the six most common ones and exactly how to fix them.
1. Vitamin B12
Why it matters: Brain function, nerve health, red blood cell formation. Deficiency causes fatigue, numbness, memory issues, and irreversible nerve damage if prolonged.
The problem: B12 is found almost exclusively in animal products. There is no reliable plant source — not spirulina, not nutritional yeast (unless fortified), not fermented foods.
The fix:
- Supplement: 2,500 mcg cyanocobalamin once per week, OR 250 mcg daily
- Fortified foods: Nutritional yeast (check label for B12), fortified plant milks, fortified cereals
- Get tested: Ask your doctor for serum B12 AND methylmalonic acid (MMA) — B12 alone can miss early deficiency
This is non-negotiable. Every vegan needs B12 supplementation. No exceptions.
2. Omega-3 Fatty Acids (EPA & DHA)
Why it matters: Brain health, inflammation regulation, heart health, eye health.
The problem: Plants contain ALA (flax, chia, walnuts), but your body converts only 5-10% of ALA to the EPA and DHA your brain actually needs. It's like trying to fill a pool with a garden hose.
The fix:
- Algae-based EPA/DHA supplement: 250-500mg combined EPA+DHA daily (this is where fish get their omega-3s — you're just cutting out the middleman)
- Brands: Ovega-3, Nordic Naturals Algae Omega, Complement
- Still eat ALA sources (flax, chia, walnuts) — they have other benefits
3. Iron
Why it matters: Oxygen transport, energy, immune function. Deficiency causes fatigue, weakness, pale skin, cold hands.
The problem: Plant iron (non-heme) is absorbed at 2-20% compared to 15-35% for meat iron (heme). You need to eat roughly 1.8x more iron than omnivores.
The fix:
- Pair iron-rich foods with vitamin C: Lentils + lemon juice, spinach + bell peppers, beans + tomato sauce. Vitamin C can increase absorption by 3-6x.
- Avoid tea/coffee with meals: Tannins block iron absorption. Wait 1 hour after eating.
- Best plant sources: Lentils, chickpeas, tofu, fortified cereals, pumpkin seeds, spinach (cooked)
- Cook in cast iron: Especially acidic foods like tomato sauce — it leaches usable iron
- Get tested annually: Ferritin levels (iron stores), not just hemoglobin
4. Zinc
Why it matters: Immune function, wound healing, taste/smell, hormone production.
The problem: Phytates in grains and legumes bind zinc and reduce absorption by up to 50%. Vegans typically need 50% more zinc than RDA suggests.
The fix:
- Soak and sprout grains and legumes — reduces phytates significantly
- Best sources: Pumpkin seeds, hemp seeds, chickpeas, lentils, cashews, fortified cereals
- Consider a low-dose supplement (15mg zinc picolinate) if you're not regularly eating these foods
- Don't mega-dose: Too much zinc depletes copper. Stay under 40mg/day.
5. Calcium
Why it matters: Bone health, muscle contraction, nerve signaling, heart rhythm.
The problem: Without dairy, many vegans get only 400-500mg daily vs. the 1,000mg recommendation. Oxalates in spinach and chard bind calcium, making them poor sources despite their high numbers on paper.
The fix:
- Fortified plant milk: Choose ones with calcium carbonate (better absorbed). Shake the carton — calcium settles at the bottom.
- Tofu made with calcium sulfate: Check the label — 1/2 cup has 400mg calcium
- Low-oxalate greens: Kale, bok choy, broccoli (absorbed better than dairy calcium, actually)
- Fortified orange juice — 350mg per glass
- Supplement if needed: Calcium citrate, 500mg with dinner (take with vitamin D for best absorption)
6. Vitamin D
Why it matters: Bone health (works with calcium), immune function, mood regulation, muscle function.
The problem: Not specifically a vegan issue — most Americans are deficient. But vegans miss the small amounts in dairy and eggs that help omnivores.
The fix:
- Supplement year-round: 1,000-2,000 IU vitamin D3 daily (look for vegan D3 from lichen — most D3 is from lanolin/sheep wool)
- Brands: Vitashine, MaryRuth's, Garden of Life
- Get tested: 25-hydroxyvitamin D blood test. Aim for 30-50 ng/mL.
- Sun exposure helps but isn't reliable (depends on latitude, skin tone, season, sunscreen)
The Simple Vegan Supplement Stack
If you want the minimum effective approach:
| Supplement | Dose | Frequency | Cost/month | |-----------|------|-----------|------------| | B12 (cyanocobalamin) | 2,500 mcg | Weekly | ~$5 | | Algae omega-3 (EPA+DHA) | 250-500mg | Daily | ~$15 | | Vitamin D3 (vegan) | 2,000 IU | Daily | ~$8 | | Zinc (picolinate) | 15mg | Daily (optional) | ~$5 |
Total: $28-33/month for nutritional peace of mind.
Calcium and iron are better obtained from food with the strategies above, but supplement if blood work shows deficiency.
"Do I Really Need Supplements? Isn't Whole Food Enough?"
I hear this a lot, and I understand the appeal of getting everything from food. But here's the reality:
- B12: impossible without supplementation on a vegan diet. Period.
- DHA/EPA: theoretically possible but practically unreliable from ALA conversion alone
- Vitamin D: a sun and lifestyle issue, not a food issue
- Iron, zinc, calcium: absolutely achievable from food with strategy
Supplements aren't a failure of your diet — they're a tool. Omnivores get B12 because their animals were supplemented with it. You're just doing it directly.
Red Flags to Watch For
See a healthcare provider if you notice:
- Persistent fatigue despite adequate sleep
- Tingling or numbness in hands/feet (B12)
- Hair loss or brittle nails (iron, zinc)
- Frequent illness (zinc, vitamin D)
- Brain fog or memory changes (B12, omega-3)
- Muscle cramps (calcium, magnesium, vitamin D)
These could have many causes — but nutrient deficiency should be ruled out, especially on a vegan diet.
Beyond Deficiency: Thriving on a Vegan Diet
Fixing gaps is step one. Step two is optimizing. A well-planned vegan diet rich in legumes, whole grains, fruits, vegetables, nuts, and seeds — with appropriate supplementation — can support everything from marathon training to pregnancy to healthy aging.
If you want personalized guidance on building a nutritionally complete vegan diet that works with your life, goals, and preferences, that's exactly what I do.
The Bottom Line
Veganism is a valid, healthy dietary choice — but it requires awareness. The six nutrients above are your non-negotiables to monitor. Get blood work annually, supplement strategically, and eat a variety of whole foods. Your body will thank you.