The evidence is clear and consistent: a well-planned vegan diet requires specific supplementation to avoid serious long-term health consequences.

A well-planned vegan diet is one of the most protective dietary patterns for long-term health. Research consistently associates it with lower rates of type 2 diabetes, hypertension, obesity, and certain cancers. But the evidence is equally clear on this point: without targeted supplementation, vegan diets carry serious risks of deficiency in several nutrients that are either absent from or poorly absorbed from plant foods.

A 2025 review published in the Journal of the American Nutrition Association identifies 10 critical nutrients at risk in vegan diets: Vitamin B12, iron, calcium, Vitamin D, iodine, zinc, omega-3 fatty acids, selenium, Vitamin A, and protein. The review states that 'proper dietary planning, including fortified foods and supplements, is essential to mitigate nutritional gaps and maintain optimal health on a vegan diet.' This is not a fringe position — it reflects the consensus of major dietetic organisations worldwide, including the British Dietetic Association, the Academy of Nutrition and Dietetics, and the European Society of Clinical Nutrition.

THE MOST CRITICAL FINDING

Vitamin B12 deficiency is not optional knowledge for vegans — it is a medical necessity. Plant- based foods contain no reliable source of Vitamin B12. A 2024 scoping review (PMC) found B12 deficiency prevalence of 52% in vegan individuals and only 1% in omnivorous individuals. Subnormal B12 status affects 50–70% of unsupplemented vegetarians and vegans across Austria, Germany, Italy, Australia, India, and China. The consequences of untreated B12 deficiency include irreversible neurological damage, macrocytic anaemia, cognitive decline, and elevated homocysteine — a major cardiovascular risk factor.

The 10 nutrients at risk — and why each one matters

Vitamin B12
CRITICAL — NO PLANT SOURCE

Completely absent from all plant foods in reliable, biologically active amounts. Only found in animal products or fortified foods. Without supplementation, deficiency is almost certain over time. Neurological damage from prolonged B12 deficiency can be irreversible.

Iodine
THYROID FUNCTION

Dairy and fish are the primary iodine sources in Western diets. Vegans who avoid fortified foods and don't use iodised salt are at high risk of deficiency. Thyroid dysfunction from iodine deficiency mimics many perimenopause symptoms.

Vitamin D
NEAR-UNIVERSAL DEFICIENCY

While D2 (ergocalciferol) is found in some mushrooms, the more potent D3 form is almost entirely absent from plant foods. Most adults — vegan or not — are insufficient, but vegans who avoid fortified dairy have even fewer dietary sources.

Zinc
HORMONE & IMMUNE SUPPORT

Present in legumes, nuts, and seeds, but phytic acid in these same foods significantly reduces bioavailability. Vegans may need up to 50% more dietary zinc than omnivores to achieve equivalent absorption. Critical for immune function, skin health, and sex hormone production.

Omega-3 (EPA+DHA)
ALA CONVERSION TOO INEFFICIENT

ALA from flaxseed, chia, and walnuts converts to EPA and DHA at only 1–5% efficiency. The brain and cardiovascular system require pre-formed EPA and DHA directly. Algae is the only plant-based direct source — the same source fish use.

Selenium
THYROID & ANTIOXIDANT

Soil selenium content varies enormously by geography. Plant foods in low-selenium regions provide very little. Selenium is critical for thyroid function and antioxidant defence — deficiency is associated with thyroid disorders and impaired immune response.

Iron
ABSORPTION 2–20% FROM PLANTS

Non-haem iron from plant foods is significantly less bioavailable than haem iron from meat. Phytates, tannins (tea/coffee), and calcium all further reduce absorption. Vegan women — especially those still menstruating — are at high risk.

Vitamin A (Retinol)
CONVERSION INEFFICIENCY

Plant foods provide beta-carotene (provitamin A), but conversion to active retinol is highly variable and often inefficient — particularly in women with genetic variants affecting conversion. True Vitamin A (retinol) is found only in animal foods.

Calcium
BONE DENSITY RISK

While calcium exists in leafy greens, tofu, and fortified foods, vegans consistently show lower calcium intake than omnivores and vegetarians. Oxalates in spinach and phytates in grains reduce absorption. Combined with often-low Vitamin D, bone density risk is significant.

Creatine
MUSCLE & BRAIN

Found exclusively in animal muscle tissue — absent from all plant foods. Vegans have significantly lower creatine stores, associated with reduced muscle strength, exercise performance, and cognitive function. Synthetic creatine supplementation is the direct solution.

What the major health organisations say

The position of global dietetic and medical organisations is consistent: supplementation is not optional for vegans, it is a medical recommendation.

• Academy of Nutrition and Dietetics (AND): 'Well-planned vegan diets... may provide health benefits... However, vegans need reliable sources of Vitamin B12.'

• British Dietetic Association (BDA): 'Vegans should take a Vitamin B12 supplement and consider Vitamin D, iodine, selenium, calcium, and omega-3 supplements.'

• European Society for Clinical Nutrition (ESPEN): Vegan diets 'require supplementation with Vitamin B12 and careful attention to... omega-3 fatty acids, Vitamin D, iodine, and zinc.'

• World Health Organization (WHO): Notes that plant-based diets require 'attention to specific nutrients' and that fortification or supplementation is required to prevent deficiency.

• PMC 2025 Review (Journal of American Nutrition Association): Explicitly identifies 10 critical nutrient gaps and states supplementation 'is essential to maintain optimal health on a vegan diet.'

How Libré® is built for plant-based women

Libré®'s formula development was shaped by the realities of plant-based nutrition. Every ingredient decision — from switching fish oil to algae omega-3, to using lichen-derived D3, to choosing methylcobalamin B12, to using zinc and magnesium in their most bioavailable chelated forms — reflects a commitment to making clinical-grade nutrition accessible to every woman, regardless of dietary choices.

• No gelatin capsules — powder format with no animal-derived encapsulation

• No lanolin D3 — lichen-derived cholecalciferol

• No fish oil — algae-derived EPA+DHA

• No animal-derived colourants or binders

• No carmine, shellac, or animal-based excipients

• Full ingredient transparency and traceable origins — published at getlibre.co/ingredients/all

Read more: Vegan diet: nutritional considerations — PMC / Frontiers in Nutrition ↗