Plant-Based Nutrient Gaps: What the Dutch Study Reveals

You’re eating more plants — that’s great for your health and the planet. But a new Dutch study finds that even a healthy plant-based diet can miss some key nutrients. The study, in MDPI Nutrients, found that people who swapped animal proteins for plant-based options got less calcium, iron, iodine, selenium, and zinc. Women and teens were most affected. These results match earlier research on plant-based nutrient gaps. These are the shortfalls that happen when you cut out animal foods. Here’s what you need to know about the most common plant-based nutrient gaps and how to fill them without giving up your plant-based values.

What the New Dutch Study Shows

The 2026 Dutch study by de Vries and colleagues looked at what happens when people replace meat, dairy, and eggs with plant-based proteins like soy, beans, and meat substitutes. The results were clear: mineral intake dropped. Calcium, iron, iodine, selenium, and zinc all fell. Women and teens — groups already more at risk for deficiencies — saw the biggest drops.

These findings match a comprehensive systematic review of 141 studies on plant-based nutrient intake. That review also found that people on plant-based diets often get less B12, vitamin D, iron, zinc, iodine, and calcium. The Dutch study adds that even a partial shift to plant proteins can create these gaps.

The 7 Key Plant-Based Nutrient Gaps to Know

Plant-based diets have many health perks. But some nutrients are harder to get. A 2025 analytical review (Malhotra & Lakade) lists these seven as key concerns. The Academy of Nutrition and Dietetics also emphasizes that careful planning is essential for plant-based diets to be nutritionally adequate — though their position focuses on overall dietary adequacy rather than a specific checklist of deficiencies. Let’s look at each plant-based nutrient gap.

1. Vitamin B12

This is the biggest gap. A 2024 meta-analysis on vitamin B12 status in vegans found that vegans who don’t take B12 have much lower levels of this vitamin. B12 is vital for nerves and red blood cells. Plants don’t make it, so all vegans need a supplement. Common guidelines recommend a daily B12 supplement for vegans. Check your levels with your doctor and follow the dosage on your supplement label. Vegetarians who eat dairy or eggs may get some, but it’s still wise to check your levels.

2. Iron

Iron from plants is harder for your body to absorb than iron from meat. A review of iron status in vegetarian adults found that 12–79% of vegetarian women have low iron stores. Up to 30% have anemia. Women who still get their period are most at risk. Pair iron-rich foods (lentils, spinach, pumpkin seeds) with vitamin C (citrus, bell peppers) to boost absorption. If your ferritin is low, talk to your doctor about the right iron dose for you.

3. Zinc

Phytates in grains and legumes can block zinc absorption. The 2021 review found that zinc intake is lower in plant-based diets. Good plant sources: pumpkin seeds, sesame seeds, chickpeas, and cashews. Soaking, sprouting, and sourdough bread make zinc more available. Most people can meet their needs with careful eating. If your diet falls short, ask your doctor about the right zinc dose for you.

4. Iodine

Iodine is tricky. A 2025 review on iodine nutrition in plant-based diets warns that vegetarians and vegans risk both too little and too much iodine. Animal foods like dairy and eggs are major sources. Without them, you may fall short — especially if you skip iodized salt. Seaweed can help, but its iodine content varies a lot. Consider a supplement at the dose your doctor recommends. Don’t exceed amounts without medical advice.

5. Calcium

The 2021 review found that vegans have the lowest calcium intake and lower bone density. Plant sources include fortified plant milks, calcium-set tofu, kale, and broccoli. But you may need 3–4 servings daily. If you can’t manage that, a supplement if needed. Ask your doctor about the right type and dose for you.

6. Vitamin D

Vitamin D levels tend to be lower in plant-based eaters, but this is common for everyone, especially in winter. Mushrooms exposed to UV light give some, but most people need a supplement. Vegan D3 (from lichen) or D2 is fine. Use the dosage that matches your blood level.

7. Omega-3 DHA

Plant-based diets give you ALA from flax, chia, and walnuts. But your body only turns about 2–5% of it into DHA (research on omega-3 fatty acid needs for vegetarians). DHA is key for your brain and eyes. Vegans should take an algae-based DHA supplement according to the label directions.

How to Fill Plant-Based Nutrient Gaps with Food First

Before reaching for supplements, try to get as much as you can from food. The Academy of Nutrition and Dietetics says well-planned plant-based diets can be nutritionally sound. Here’s a food-first approach for each plant-based nutrient gap:

• B12: Fortified plant milks, nutritional yeast, cereals. But you still need a supplement.
• Iron: Lentils, chickpeas, spinach, pumpkin seeds. Add vitamin C (like lemon) to boost absorption.
• Zinc: Pumpkin seeds, cashews, chickpeas, sourdough bread.
• Iodine: Iodized salt, small amounts of seaweed (like nori), fortified plant milks.
• Calcium: Fortified plant milks (aim for 300 mg per cup), calcium-set tofu, leafy greens.
• Vitamin D: UV-exposed mushrooms, fortified foods. But take a supplement when sun is low.
• DHA: ALA from flax and chia, but rely on an algae supplement for DHA.

Many of these nutrient-dense foods also make excellent heart healthy snacks to keep on hand for busy days.

Strategic Supplementation: When and How Much

The dosages below are general recommendations from clinical practice. Always check with your healthcare provider before starting a new supplement, especially if you are pregnant, nursing, or on medications. For a complete overview of supplement options tailored to women’s health, check out our guide to the best supplements for women. Here’s a simple guide for closing plant-based nutrient gaps with supplements:

• Vitamin B12: A daily B12 supplement is essential for vegans. Common guidelines recommend a daily B12 supplement. Check your levels with your doctor and follow the dosage on your supplement label.
• Vitamin D: Use the dosage that matches your blood level. Vegan D3 from lichen works.
• Iron: Only take if your ferritin is low. Talk to your doctor about the right dose and schedule for you.
• Zinc: If your diet falls short, ask your doctor about the right zinc dose for you.
• Iodine: If you don’t use iodized salt, consider a supplement at the dose your doctor recommends. Don’t exceed amounts without medical advice.
• Calcium: A supplement if needed. Ask your doctor about the right type and dose.
• DHA: An algae-based DHA supplement according to the label directions.

The Academy of Nutrition and Dietetics position on vegetarian and vegan dietary patterns suggests working with a dietitian to tailor your plan.

A Simple Daily Checklist for Plant-Based Nutrient Gaps

Print this list and stick it on your fridge. It takes two minutes to check off. It can save you from the long-term effects of not filling plant-based nutrient gaps — like fatigue from low iron, weak bones from low calcium, or thyroid issues from low iodine.

The Bottom Line

Plant-based eating can be a smart choice for your health and the planet. The Dutch study adds to the evidence that plant-based nutrient gaps are real. But they’re not a reason to give up plants. Instead, they’re a signal to be intentional. By knowing which plant-based nutrient gaps matter most for women, choosing the right foods, and supplementing where needed, you can enjoy all the perks of a plant-forward lifestyle without sacrificing your health.

Awareness and a bit of daily planning go a long way. You’ve got this.