Research shows that older adults following long-term vegan diets often don’t get enough protein and key nutrients like vitamin B12, calcium, and vitamin D. According to Gram Research analysis of a 2026 study of 26 older Dutch adults, 83% of vegans and 40% of vegetarians had inadequate protein intake, and nearly all had low protein quality scores. However, the study notes that well-planned plant-based meals can provide adequate nutrition with proper guidance.
A new study of Dutch older adults who have followed vegetarian and vegan diets for decades found that many aren’t getting enough protein, calcium, zinc, and vitamin B12. Researchers looked at what 20 vegetarians and 6 vegans, all around 76 years old, ate over three days and compared it to meat-eaters. While plant-based diets have health benefits, the study shows that older adults following these diets need better meal planning to avoid nutritional gaps. The good news: with the right food combinations, plant-based diets can provide adequate nutrition.
Key Statistics
A 2026 cross-sectional study of 26 older Dutch adults found that 83% of vegans and 40% of vegetarians weren’t meeting recommended protein intake, compared to 25% of meat-eaters.
According to research reviewed by Gram, 100% of vegans and 83% of vegetarians in the study had low protein quality scores across the day, meaning their protein sources weren’t optimally complete.
The 2026 study found that both vegetarians and vegans failed to meet recommended intakes for calcium, zinc, vitamin B12, and vitamin D, with vegans additionally falling short on iron and folate.
Among 6 vegans studied who had followed their diet for an average of 10 years, the median daily protein intake fell below recommended amounts in 5 participants, highlighting the importance of careful meal planning.
The Quick Take
- What they studied: Whether older adults who have eaten vegetarian or vegan diets for many years are getting enough protein and important vitamins and minerals from their food.
- Who participated: 26 older Dutch adults (average age 76): 20 who had been vegetarian for about 42 years on average, and 6 who had been vegan for about 10 years. They were compared to a reference group of meat-eaters.
- Key finding: According to Gram Research analysis, 83% of vegans and 40% of vegetarians weren’t eating enough protein compared to recommended amounts, and most weren’t getting adequate amounts of calcium, zinc, vitamin B12, and vitamin D.
- What it means for you: If you’re an older adult following a plant-based diet, you may need to pay closer attention to what you eat to ensure you’re getting enough protein and key nutrients. Working with a nutritionist familiar with plant-based eating can help prevent deficiencies.
The Research Details
Researchers conducted a cross-sectional study, which is like taking a snapshot of people at one point in time rather than following them over years. They asked 26 older Dutch adults (20 vegetarians and 6 vegans) to write down everything they ate for three days. The researchers then analyzed these food records to count how much protein, vitamins, and minerals each person consumed.
To measure protein quality, they used two scoring systems: the Meal Protein Quality Score (MPQS), which looks at how good the protein is in each meal, and the Protein Adequacy and Quality Score (PAQS), which looks at protein quality across the whole day. They compared the plant-based eaters to a reference group of older adults who eat meat.
The study focused on Dutch older adults specifically because they wanted to understand the long-term effects of plant-based diets in people who had followed them for decades—some vegetarians for 42 years and vegans for 10 years.
This research approach is important because it shows real-world eating patterns of people who have committed to plant-based diets for a very long time. Rather than studying people for just a few weeks or months, researchers looked at people who had been vegetarian or vegan for decades, which gives a clearer picture of whether these diets can meet nutritional needs over the long term. Understanding these patterns helps doctors and nutritionists identify which nutrients older plant-based eaters might be missing.
This study has some important limitations to consider: it’s relatively small (only 26 people), which means the results may not apply to all older adults. The study only looked at Dutch people, so results might differ in other countries with different food availability. Food records depend on people remembering and accurately reporting what they ate, which can be imperfect. However, the study’s strength is that it examined people with very long-term adherence to plant-based diets, providing valuable real-world data.
What the Results Show
The study found striking differences in protein intake between groups. Among vegans, 83% weren’t eating enough protein according to recommended daily amounts. For vegetarians, 40% fell short of protein recommendations, compared to just 25% of meat-eaters. This gap matters because protein is especially important for older adults to maintain muscle mass and strength.
When researchers looked at protein quality—meaning how complete and useful the protein is for the body—the picture was even more concerning. Nearly all vegans (100%) and most vegetarians (83%) had low overall protein quality scores across the day. This means that even when they were eating some protein, it wasn’t always the best type for their bodies to use effectively.
The sources of protein differed between groups. Vegetarians got most of their protein from dairy products like cheese and yogurt, while vegans relied on dairy replacers (like plant-based milks), gluten-based products, and soy products. The study found that vegans had lower overall energy intake and ate more carbohydrates and fat compared to meat-eaters.
Beyond protein, the study identified multiple micronutrient gaps. Both vegetarians and vegans failed to meet recommended intakes for calcium, zinc, vitamin B12, and vitamin D. Vegans additionally fell short on iron and folate. These nutrients are crucial for bone health, immune function, energy, and blood health—all especially important in older age. Interestingly, vegetarians had comparable total energy intake to meat-eaters but with different proportions of nutrients, while vegans consumed less total energy overall.
This research aligns with previous studies showing that plant-based diets can pose nutritional challenges, particularly for vulnerable populations like older adults. However, this study adds important new information by examining people with very long-term adherence (decades) rather than recent diet adopters. The findings support existing nutritional guidance that plant-based eaters need careful meal planning, but also suggest that the challenge may be greater for older adults whose nutritional needs are already higher.
The study is small, with only 26 participants, so findings may not represent all older plant-based eaters. It only included Dutch adults, so results may differ in other countries with different food cultures and availability. The study relied on 3-day food records, which may not represent typical eating patterns—people might eat differently on the days they were recording. The study didn’t include information about supplements, which many plant-based eaters take to fill nutritional gaps. Finally, this is a snapshot study, not a long-term follow-up, so we can’t determine whether these nutritional gaps actually caused health problems.
The Bottom Line
Older adults following vegetarian or vegan diets should work with a registered dietitian to ensure they’re meeting protein and micronutrient needs. Key strategies include: combining different plant proteins throughout the day (beans, nuts, seeds, soy, grains), considering fortified foods or supplements for vitamin B12 and vitamin D, eating calcium-rich foods like fortified plant milks or leafy greens, and ensuring adequate iron intake through plant sources paired with vitamin C. These recommendations have moderate to strong evidence support.
This research is most relevant to older adults (65+) following vegetarian or vegan diets, their family members, and healthcare providers. It’s particularly important for vegans, who showed more significant nutritional gaps than vegetarians. Younger plant-based eaters may have different nutritional needs and may find it easier to meet requirements. People with existing health conditions affecting nutrient absorption should pay special attention.
Nutritional deficiencies don’t develop overnight. However, vitamin B12 stores can become depleted over months to years without adequate intake. Bone health effects from calcium and vitamin D deficiency develop gradually over years. The good news: with proper meal planning or supplementation, you can prevent these problems from developing. Benefits of improved nutrition may include better energy, stronger bones, and improved muscle maintenance within weeks to months.
Frequently Asked Questions
Can older adults get enough protein on a vegan diet?
Research shows it’s challenging but possible. A 2026 study found 83% of older vegans weren’t meeting protein needs, but the researchers noted that well-composed plant-based meals combining different protein sources can provide adequate protein. Working with a dietitian is recommended.
What nutrients do older vegetarians and vegans need to watch out for?
According to Gram Research analysis, the main concerns are vitamin B12, vitamin D, calcium, and zinc for both groups, plus iron and folate for vegans specifically. These nutrients are critical for bone health, immune function, and energy in older age.
Is a vegetarian diet safer than a vegan diet for older adults?
A 2026 study found vegetarians had fewer nutritional gaps than vegans, likely because dairy products provide protein, calcium, and B12. However, 40% of vegetarians still had inadequate protein intake, suggesting both diets require careful planning in older age.
How can older vegans improve their protein intake?
Combine different plant proteins throughout the day: beans with grains, tofu with nuts, or lentils with seeds. Include fortified plant milks and consider supplements for B12 and vitamin D. A dietitian can help create personalized meal plans.
Do supplements help older plant-based eaters meet nutritional needs?
The 2026 study didn’t track supplement use, but vitamin B12 and vitamin D supplements are generally recommended for vegans. Consulting a healthcare provider about which supplements are appropriate for your individual needs is important.
Want to Apply This Research?
- Track daily protein intake (target: 1.0-1.2g per kg body weight for older adults) and log sources of key nutrients: vitamin B12 (fortified foods or supplements), calcium (fortified plant milks, leafy greens), vitamin D (fortified foods or supplements), iron (beans, lentils, fortified cereals), and zinc (nuts, seeds, legumes). Use the app’s nutrient tracking feature to identify gaps.
- Create a meal-planning template that combines at least two plant protein sources per meal (for example: beans + whole grains, tofu + vegetables + nuts). Set weekly reminders to check B12 and vitamin D supplement intake. Log one new plant-based protein recipe weekly to increase variety and nutrient density.
- Monthly nutrient score review comparing actual intake to recommended amounts. Quarterly check-ins with blood work if possible (B12, vitamin D, iron levels). Track energy levels and muscle strength monthly as practical indicators of adequate protein intake. Annual review with a dietitian to adjust meal plans based on changing needs.
This research describes nutritional patterns in a small study of Dutch older adults and should not be considered medical advice. Individual nutritional needs vary based on age, health status, medications, and other factors. Older adults considering or following plant-based diets should consult with their healthcare provider or a registered dietitian to assess their individual nutritional status and determine appropriate supplementation or dietary modifications. This article is for informational purposes and does not replace professional medical or nutritional guidance. Anyone experiencing symptoms of nutritional deficiency should seek medical evaluation.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
