Vegetarian and Vegan Diets

Section: Health | Vida Vertical

Summary

Plant-based dietary patterns have become increasingly widespread for health, ethical, environmental and cultural reasons. This article distinguishes several vegetarian patterns, examines their nutrient profiles and identifies nutrients that require particular attention, including vitamin B12, iodine, iron, calcium, selenium, vitamin D, omega-3 fatty acids and protein. It explains how a well-planned diet can meet needs during everyday life and sport and considers controlled cultivation as one possible source of fresh produce.

1. Introduction: The Diversity of Plant-Based Diets

Plant-based diets have grown in popularity for many reasons. Alongside personal health, performance or preference, concern for animals, climate, land use and future generations may influence food choices. These motivations differ between individuals and do not determine the nutritional quality of the diet by themselves.

2. Types of Vegetarian Diet

“Vegetarians do not eat meat” is a useful starting point but does not capture the range of practice. The following labels describe commonly included and excluded animal-derived foods; individual definitions may vary:

The prefixes derive from Latin roots: piscis refers to fish, ovum to egg and lact- to milk. “Pescatarian” is not universally classified as vegetarian, so clear descriptions are preferable to relying on labels alone.

3. Protein: A Foundation of Plant-Based Nutrition

3.1 Physiological Roles

Proteins provide amino acids used in muscles, connective tissue, enzymes, transport proteins, immune components and many other structures. Athletes may require more protein to support adaptation and recovery, but hair and nails are not meaningfully “strengthened” simply by exceeding requirements.

3.2 Requirements and Provision

German guidance gives 0.8 g/kg/day as a reference for many adults aged 19–64, with different values for older adults and higher ranges often used in sport. Well-planned vegetarian and vegan diets can provide sufficient protein, but individual athletes do not prove adequacy for everyone; total intake, energy availability, digestibility and food variety matter.

3.3 Complementary Protein Sources

Plant foods offer many protein sources. Combining pulses and grains across meals can provide a balanced indispensable-amino-acid pattern, but deliberate pairing in every meal is unnecessary when overall intake is sufficient and varied.

Pulses and Soy Foods: Lentils, peas, chickpeas, beans, tofu and tempeh are rich in protein and lysine. Lysine participates in protein synthesis like every indispensable amino acid; broad claims that one food specifically drives hormones or wound healing should be avoided.

Grains and Pseudocereals: Spelt, quinoa, brown rice, oats, wholegrain bread and pasta contribute protein, carbohydrate, fibre and micronutrients. Satiety depends on portion, preparation and the whole meal rather than carbohydrate chain length alone.

Seeds and Nuts: Linseed, chia, hemp, pumpkin and sunflower seeds, peanuts, walnuts, cashews, almonds, pistachios and hazelnuts contribute protein, unsaturated fats and micronutrients. They are energy-dense, so portions can be adapted to individual needs.

4. Omega-3 Fatty Acids in Plant-Based Diets

4.1 Physiological Roles

Omega-3 and omega-6 fatty acids include essential fats and serve as precursors to signalling molecules. It is inaccurate to label omega-3 as simply anti-inflammatory and omega-6 as pro-inflammatory: both families have multiple functions, and linoleic acid intake is not consistently associated with greater inflammation in humans.

4.2 The Overall Fatty-Acid Pattern

Western diets often provide much more linoleic acid than long-chain omega-3. The practical priority is adequate ALA and, where appropriate, EPA and DHA—not pursuing a fixed ratio or broadly restricting nutritious omega-6 foods. Claims that this alone strengthens immunity, lowers cortisol or improves insulin sensitivity are not established.

4.3 Plant and Algal Sources

Oily fish accumulate EPA and DHA through aquatic food webs. Microalgae-derived oils provide a direct vegan source of DHA and sometimes EPA. Edible seaweeds are not reliable equivalents and may contain excessive iodine, so “eat algae” is not interchangeable with using a standardised algal-oil product.

Walnuts, chia, linseed, hemp and their oils provide ALA, but a quoted walnut ratio does not determine overall health value. People with nut allergy can use seed oils or consider an appropriate algae-derived supplement rather than a nonspecific supplement.

4.4 Conversion and Supplementation

Conversion of ALA to EPA is limited and conversion to DHA is usually lower, with substantial individual variation. Algal DHA/EPA can be useful for vegans and vegetarians, especially during pregnancy or when intake needs particular attention, but supplementation should reflect guidance, dose and clinical context rather than being automatically required for every person.

5. Vitamin B12: An Essential Consideration in Vegan Diets

5.1 Physiological Roles

Vitamin B12 is required for normal blood formation, DNA synthesis and neurological function. Deficiency can damage the nervous system, sometimes irreversibly; descriptions should focus on these established roles rather than suggesting that B12 directly “builds” spinal-cord nerve cells.

5.2 Requirements and Deficiency

The DGE estimates an adequate adult intake of 4.0 micrograms/day, with age- and life-stage-specific values. Deficiency may cause megaloblastic anaemia, fatigue, glossitis, sensory changes, impaired gait or cognitive symptoms. Hair loss and “damaged protein metabolism” are nonspecific and should not be presented as defining signs.

5.3 Vegan Diets

Unfortified plant foods do not provide a reliable amount of biologically active B12. Farmed animals may receive supplemented feed, but ruminants can also obtain B12 from microbial synthesis when cobalt supply is adequate. People following vegan diets need a reliable supplement or sufficiently fortified foods; some vegetarians and people with absorption problems also require supplementation. Cyanocobalamin is well studied and stable, while other forms are available.

6. Minerals and Other Nutrients Requiring Attention

Well-planned plant-based diets can supply many vitamins and minerals, yet attention may be needed for B12, iodine, iron, zinc, calcium, selenium, vitamin D, riboflavin, protein and long-chain omega-3 depending on food choices and life stage.

Vitamin D: Vitamin D status depends on sunlight, season, skin exposure, latitude, age and diet. Supplementation is not automatically recommended for everyone in every dietary group; national guidance and individual risk should guide testing or intake.

Vitamin K, Iodine and Selenium: Vitamin K2 is not generally treated as a universal critical nutrient in plant-based diets. Iodised salt in moderate amounts and appropriately dosed supplements can provide iodine; seaweed varies too widely for casual dosing. Selenium content of plant foods depends strongly on soil, and Brazil nuts are highly variable, so repeated large servings can cause excessive intake.

7. The Vida Vertical Perspective: Plant-Based Eating and Controlled Cultivation

From an aquaponics and hydroponics perspective, controlled production can improve access to selected fresh foods, but it does not by itself optimise an entire vegetarian or vegan diet:

1. Protein VarietyPea shoots and some bean crops can be grown in controlled systems, but mature dry lentils, beans and grains are generally inefficient aquaponic crops. Microgreens contribute nutrients and some protein, but typical portions do not replace staple protein foods. Pulses, soy foods, grains, nuts and seeds from broader agriculture remain central.

2. Omega-3 from MicroalgaeProducing food-grade EPA- or DHA-rich microalgae requires suitable strains, controlled photobioreactors, contamination monitoring and processing. It is not a simple extension of a household aquaponic loop. Commercially standardised algal oil is a more reliable option for most consumers.

3. Fresh Micronutrient-Rich ProduceShort harvest-to-plate times may preserve some sensitive nutrients, but conventional vegetables are not necessarily substantially depleted. Vitamin C and folate vary with crop and storage, while iron and calcium are minerals and are not destroyed by light or transport. Hydroponics does not automatically ensure maximum content or bioavailability.

4. Fermentation and B12Sauerkraut and kimchi can contain useful fermentation products and live organisms when unpasteurised, but they are not reliable sources of active vitamin B12. Vegan B12 provision must continue to rely on supplements or appropriately fortified foods.

5. Transparency and Process Control5. Responsible Crop Protection

Closed systems may reduce some herbicide and pesticide needs, but pests still occur and residue-free status requires evidence. Pesticide residues do not generally explain phytate-related iron or zinc absorption; soaking, sprouting, fermenting and meal composition are more relevant to mineral bioavailability.6. Availability across the Year

8. Conclusion

Vegetarian and vegan diets can meet nutritional needs, including for many athletes, when appropriately planned. Protein comes from sufficient varied sources; long-chain omega-3 can be obtained from algae-derived products where appropriate; and a reliable vitamin B12 source is mandatory for vegan diets. Iodine, vitamin D, iron, calcium, zinc and selenium also deserve attention.

Switching from a diet dominated by fast food to a varied plant-based pattern may support health and weight management, but outcomes are not absolute and muscle gain still requires appropriate training, energy and protein. Fresh home-grown produce can help, but it is not necessary for a nutritious, sustainable and enjoyable plant-based diet.

Note: This article provides general scientific information and is not a substitute for individual dietetic advice. Clinical or dietetic support is advisable with existing illness, during pregnancy or breastfeeding, for children, or when changing to a fully plant-based diet. B12 intake must be reliable and status should be assessed when clinically appropriate.

References:

• Roberson, D. (2017). Vegan diets: practical advice for athletes and exercisers. Journal of the International Society of Sports Nutrition, 14, 36.
• German Nutrition Society (DGE): D-A-CH reference values for nutrient intake. www.dge.de
• Pawlak, R., et al. (2014). The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. European Journal of Clinical Nutrition, 68(5), 541–548.
• Saini, R. K. & Keum, Y.-S. (2018). Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance. Life Sciences, 203, 255–267.
• Mariotti, F. & Gardner, C. D. (2019). Dietary Protein and Amino Acids in Vegetarian Diets – A Review. Nutrients, 11(11), 2661.

Author: Uwe | Vida Vertical – Health