4 critical nutrients in a vegan diet and when to consider a dietary supplement
Did you know that even the most careful vegans can develop deficiencies in essential nutrients?
Although a well-planned 100% plant-based diet offers many health benefits, certain micronutrients can be more difficult to obtain without external support.
Knowing which ones they are and how to ensure you're not missing them helps you maintain adequate levels in your body.
Let's explore the main critical nutrients in a vegan diet, why they matter, and how dietary supplements and fortified foods can help you cover them properly.
Why some vegan diets can lead to deficiencies
A 100% plant-based diet can be very balanced, but certain nutrients have lower availability or are absent in non-fortified plant foods.
Scientific study
Recent studies show that vegans are at greater risk of vitamin B12, vitamin D, and preformed omega-3 (EPA/DHA) insufficiency, as well as potentially lower intakes of minerals such as iron, zinc, calcium, or iodine[1].
This does not mean a vegan diet is inadequate, but that it requires planning and, in some cases, support through dietary supplements or fortified foods.
Critical vitamins and minerals
Vitamin B12: One of the most common
Vitamin B12 is essential for red blood cell formation and the maintenance of the nervous system. Its deficiency can develop slowly, so some vegans may feel fine despite having low levels.
Since it is not reliably found in non-fortified plant foods, and traditional sources like algae or fermented foods do not always provide bioavailable B12, supplementation is often the safest way to maintain adequate levels.
Scientific study
A 2024 study published in Nutrients, titled “Nutrient Intake and Status in Adults Consuming Plant-Based Diets Compared to Meat-Eaters: A Systematic Review,” confirms that vegans and vegetarians frequently show low vitamin B12 levels, and that appropriate supplementation can be effective in preventing B12 deficiency[2].
At Anastore you can find Vegan Vitamin B12 in cyanocobalamin form, obtained through natural fermentation, in a practical dose to maintain good levels. Regular intake is recommended, and if possible, monitoring of blood markers (B12, homocysteine, MMA).
Vitamin D: geographical and seasonal factors
Vitamin D is synthesised in the skin through sun exposure. Latitude, season, skin tone, and lifestyle influence production, which explains why many vegans have suboptimal levels during winter or in low-sunlight regions.
Although fortified foods exist, vegan versions of vitamin D (D2 or D3 from lichen) can be useful for those unable to meet their needs via diet or sunlight.
Plant-based Vitamin D3 from Anastore, suitable for vegans, can be useful in months with low solar radiation or for those who do not get enough vitamin D from fortified foods.
Omega-3 (EPA/DHA) in a vegan diet: beyond ALA
Common plant sources of omega-3, such as flaxseed, chia, or walnuts, provide alpha-linolenic acid (ALA), a precursor that the body must convert into EPA and DHA. However, this conversion is limited and highly variable between individuals, especially in postmenopausal women, people with inflammation, or those with unbalanced diets.
For this reason, more and more research recommends that vegans consider direct sources of EPA/DHA from microalgae, as they are structurally identical to those in fish and seafood but 100% plant-based.
Omega-3 DHA from Anastore is a 100% plant-based supplement with DHA obtained from microalgae, ideal for vegans who want to meet their needs without relying on ALA conversion. It is often recommended for:
- Improving direct DHA intake
- Supporting brain and visual function
- Balancing lipid profile
- Compensating for low EPA/DHA intake due to lack of fish
Plant-based iron: a classic
Plant-derived iron has lower bioavailability compared with “heme” iron from animal sources. Its absorption improves when combined with vitamin C and can be affected by phytates or inhibitory compounds present in whole grains or legumes.
Scientific study
A randomized double-blind study published in 2025 in Cureus, titled Efficacy of plant-based iron and vitamin C in adults with iron deficiency anemia, showed that plant-based iron combined with vitamin C significantly improved hemoglobin and ferritin levels in adults with iron deficiency anemia[3].
At Anastore you can purchase Iron and Vitamin C, an ideal supplement for diets low in legumes or iron-rich vegetables, already combined with vitamin C for optimal absorption.
Other interesting nutritional options
Beyond the critical nutrients, some vegan foods and supplements can further support the diet, such as Anastore's organic spirulina, a plant-based source rich in protein, iron, and minerals.
At Anastore you have a list of dietary supplements suitable for vegans that may be of interest.
Integrating vegan-friendly dietary supplements helps cover common deficiencies in a practical way.
The key is to use supplements as support, maintaining a balanced diet and monitoring blood levels of critical nutrients when possible. In this way, a well-planned vegan diet can be healthy, sustainable, and complete.
Bibliography
- Various authors. Nutritional Status of Plant Based Diets. 2022. See study
- Various authors. Exploring Vitamin B12 Supplementation in the Vegan Population: A Scoping Review of the Evidence. Nutrients. 2024. See study
- Maheshvari N. Patel, Nayan Patel, Jit Maheshvari. Efficacy of Plant-Based Iron and Vitamin C in Adults With Iron Deficiency Anemia: A Randomized, Double-Blind Clinical Study. Cureus. 2025. See study