Vegan nutrition: what it can do, and what gets tight after years
Eating plant based can ease the load on almost any body. Supply is a different question from relief, though, and it shows up late. Here both stand side by side, with numbers.
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Eating plant based can ease the load on almost any body. That is measurable in good studies. Only, relief and supply are two different things. Stores and backup synthesis can fake normality for years. The gap shows up late.
There is one conversation I keep having. Someone has been eating vegan for six years and says: I have never felt better. And that is usually true.
Then comes the second part. For about a year now there has been this tiredness. Nothing dramatic. Just not the old level any more.
I do not want to talk you out of how you eat. Anyone living vegan for ethical reasons has good reasons, and I do not judge them. What I am showing you is what shifts over the years and which values could flag it early. The message is not: stop this. It is: do it with open eyes.
What to expect here
- Why the first months almost always feel good
- Heart benefit and stroke signal from the same cohort
- Why a normal B12 value proves little
- The bioavailability bundle: iron, zinc, iodine, selenium
- The overlooked group: choline, creatine, carnosine, taurine
- Protein quality, leucine and the fracture numbers
- What well planned means and who it suits
The first months almost always feel good
Do you know that feeling when the afternoon slump stops showing up two weeks into a change? Lighter, more awake, less bloated. Many people describe it. It often has a different cause than assumed.
When you eat purely plant based, sausage, ready meals and a large share of the sugar disappear almost automatically. What is left is more vegetables, legumes, nuts and fibre.
Kevin Hall and his team at the US National Institutes of Health had 20 adults eat ultra-processed food for two weeks and unprocessed food for two weeks as inpatients, with calories, sugar and fibre matched.
In the ultra-processed phase they ate 508 kilocalories more per day and gained 0.9 kilograms, in the unprocessed phase they lost 0.9 kilograms.
For you that means: a large part of your first effect can come from what you left out, not from the plant part itself.
Hall KD et al. Cell Metab. 2019. DOI: 10.1016/j.cmet.2019.05.008 [RCT, n=20]A series of systematic reviews covering 185 cohorts and 58 randomised trials found 15 to 30% lower all-cause mortality with a high fibre intake, plus less heart disease, stroke, type 2 diabetes and bowel cancer. The largest benefit sat at 25 to 29 grams per day. Eating plant based, you reach that almost in passing, more on that in Fibre: what the reputation promises.
And the microbiome: reported are more diversity and more short-chain fatty acids such as butyrate. The review behind this, though, comes from an author group with a declared plant based orientation. The direction is supported, the source is not neutral.
The first effect is rarely a vegan effect. Often it is a leaving-out effect.
If the gain hangs on dropping ultra-processed products, you can keep it without joining a camp. See Unprocessed food and satiety and The calorie myth.
So much for the good months. They say nothing about supply.
The big studies, when you name both numbers
You may have read both headlines. One says vegans live longer. The other says vegans break their hips more often. Both numbers often come from the same study. Rarely does anyone name them together.
At Stanford University, in 22 pairs of identical twins one twin ate a healthy vegan diet for eight weeks while the other ate a healthy omnivorous one. That neutralises genetics and a large part of the early imprinting.
In the twins eating vegan, LDL cholesterol fell by 13.9 mg/dl, fasting insulin by 2.9 µIU/ml and body weight by 1.9 kilograms.
For you that means: the cardiometabolic improvement appears to be more than a lifestyle artefact. What an LDL value actually says is covered in Cholesterol: the science behind the myth.
Landry MJ et al. JAMA Netw Open. 2023. DOI: 10.1001/jamanetworkopen.2023.44457 [RCT, n=44]EPIC-Oxford followed almost 48,000 people over 18 years.
22% less ischaemic heart disease, that is 10 fewer cases per 1000 over ten years.
20% more strokes in the same group, mostly haemorrhagic ones, that is 3 more cases per 1000.
The stroke signal did not disappear after adjustment. Low LDL, low B12 and a low taurine status are discussed as candidates. None of these explanations is proven. I am leaving it standing as an open question.
With mortality a second look is worth it. In the Adventist Health Study 2 with 73,308 participants, all-cause mortality across all vegetarians came to a hazard ratio of 0.88. For vegans alone the benefit was formally not significant, the confidence interval reached just above 1. This nuance gets lost in almost every popular account.
One finding rarely fits the picture: in a German cross-sectional study with 36 vegans and 36 mixed eaters, seven inflammatory markers did not differ. The longer someone had lived vegan, the higher resistin, interleukin-18 and IL-1 RA were. A correlation in a small sample, not proof. It does fit the pattern, though: what eases the load at first does not have to stay that way over the years.
A study is not a verdict on a way of eating. It is a measurement under particular conditions.
Quoting only the heart benefit creates false safety. Quoting only the fracture numbers creates fear. I am deliberately leaving out the psychological layer, it belongs in Eating vegetarian: what happens over the long run.
That gives you the frame. From here on it is about the mechanisms.
Vitamin B12: why a normal value proves little
Your GP measured B12. The value sits inside the reference range. All good, right? Perhaps not.
Picture your bank account. The statement says 10,000 euros, but 8,000 of that is tied up in a fixed deposit. Available: 2,000.
Vitamin B12 works exactly like that. Around 80% of serum B12 is bound to haptocorrin and is not available to your cells. Only 6 to 20% is bound to transcobalamin, and that is the active fraction, measured as holo-transcobalamin.
Cobalamin is a cofactor for exactly two enzymes. When it is functionally missing, homocysteine and methylmalonic acid rise. These two show function. Total B12 shows only quantity.
That is why methylmalonic acid and holo-transcobalamin are the more informative markers, especially together. An international consensus primer stresses at the same time that the exact cut-offs are debated among experts. There is no undisputed number here.
Roman Pawlak and colleagues analysed 18 studies that defined B12 deficiency via methylmalonic acid or holo-transcobalamin, not via serum B12 alone.
Deficiency rates were 62% among pregnant vegetarians, 25 to 86% among children, 21 to 41% among adolescents and 11 to 90% among older people.
For you that means: the storage effect is real, but finite. Anyone living for a long time without supplementing can eventually slip.
Pawlak R et al. Nutr Rev. 2013. DOI: 10.1111/nure.12001 [Systematic Review, k=18]The good news sits in German data. In the Berlin study by the Federal Institute for Risk Assessment, nearly all vegans had been supplementing beforehand, and their B12 biomarkers did not differ from those of mixed eaters. So supplementing can work well.
Normal is not the same as supplied. A value inside the reference range describes a quantity, not a function.
If you have been living vegan for years and supplement B12, the interesting question is not your serum B12. It is: is your methylmalonic acid low?
So much for the best known point. The harder one hangs on an absorption route.
The bundle: iron, zinc, iodine and selenium belong together
Many people know this pattern. They supplement iron, the value barely moves. Then zinc, and little happens. Usually it is not one nutrient that is missing. Often an absorption route is slowed, and that route can affect several minerals at once.
Phytate is the storage form of phosphorus in seeds, grains and legumes. Chemically it is a gripping arm with six phosphate groups. It binds minerals in the gut, and what is bound does not pass through the gut wall. Polyphenols from coffee, tea and cocoa do something similar.
On the other side stand the enhancers. Vitamin C with the same meal can lift iron absorption noticeably. In numbers: estimated iron availability of 14 to 18% from a mixed diet compared with 5 to 12% from a vegetarian diet. The same mechanism hits zinc.
In a meta-analysis of 24 cross-sectional studies, ferritin in vegetarians was on average 29.7 µg/l lower, and 61.9 µg/l lower in men. Everything further on that is in Iron deficiency on a vegan and vegetarian diet.
Zinc follows the same principle. In a meta-analysis of 26 studies, zinc intake was 0.88 mg per day lower and serum zinc 0.93 µmol/l lower. Not much, but it can shift an entire group towards the lower third of the reference range.
The Federal Institute for Risk Assessment in Berlin compared 36 vegans with 36 mixed eaters, using basic labs, trace element status and 24-hour urine.
For B12, vitamin D and iron there was no group difference, because nearly all vegans were supplementing. In one third of the vegans, iodine excretion sat below the WHO threshold for severe iodine deficiency.
For you that means: supplementing can work well where people think of it. Iodine is the gap almost nobody thinks of.
Weikert C et al. Dtsch Arztebl Int. 2020. DOI: 10.3238/arztebl.2020.0575 [Cohort, n=72]Plus a detail almost nobody knows. In a Boston study of 140 people, urinary iodine in vegans had a median of 78.5 µg/l compared with 147.0 µg/l in vegetarians, and thiocyanate was clearly higher. Thiocyanate arises from glucosinolates in cabbage, broccoli and rocket, and it competes with iodine for the same transporter in the thyroid. Of all things, the vegetables you eat more of can slow iodine uptake. TSH and free T4 did not differ here: no alarm, but a reason to measure.
Selenium usually goes unmentioned. In German data, selenoprotein P was lower in vegans, and that is the better status marker. Why trace elements carry so much weight in energy metabolism is covered in From calorie to energy: the cofactors.
Rarely is a single nutrient missing. Often an absorption route is slowed, and that route can affect a whole bundle.
Soaking, sprouting, sourdough and fermenting can lower the phytate content. Separating coffee and tea in time from your main meal costs nothing. Directions, not recipes, and no substitute for a measurement.
That is how several minerals get tighter at the same time.
Choline, creatine, carnosine, taurine: the overlooked group
Ask ten people what vegans might be missing. Nine say B12, maybe iron. Almost nobody names these four. What they share: your body can make them itself, but at a lower level. Experts speak of conditionally essential, a way of thinking rather than a hard category.
Choline: the strongest signal in this group
Choline sits above all in eggs and liver. It is a building block of every cell membrane, of the messenger acetylcholine and of fat transport out of the liver. When it is missing, fat can stay behind in the liver.
A team at the University of North Carolina put 57 adults on a controlled diet very low in choline and measured liver fat by MRI.
Under choline depletion, 77% of the men and 80% of the postmenopausal women developed fatty liver or muscle damage, but only 44% of the premenopausal women.
For you that means: estrogen can raise the body's own phosphatidylcholine production. Men and women after menopause are less protected.
Fischer LM et al. Am J Clin Nutr. 2007. DOI: 10.1093/ajcn/85.5.1275 [RCT, n=57]For context: this study did not run in vegans. In a US intake survey of 16,809 people, only 10.8% reached the recommended choline intake. Choline is already tight in the general population, and anyone who cuts eggs and liver cuts the two richest sources. The link between vegan eating and choline remains a plausible inference, not a direct measurement. See also Organ meats, bone broth and the forgotten parts.
Creatine: three studies, three voices
The first voice, 2003: 45 young adults living vegetarian, 5 grams of creatine monohydrate daily over six weeks, double blind in a crossover design. Working memory and fluid intelligence improved clearly. The whole narrative rests on it.
The second voice, 2023: same design, but 123 participants and preregistered. The effects were small and formally not significant, side effects more frequent, and vegetarians did not benefit more than mixed eaters. The third voice sits in between: a systematic review of six randomised trials with 281 people, with hints of better short-term memory and otherwise inconsistent results.
Consistently documented, by contrast, is the muscle. In a randomised trial with 40 women, plasma and muscle creatine fell without supplementation after just three months. In a review of nine studies, creatine raised muscle stores, lean mass and maximal strength. Phosphocreatine in the brain did not change.
The muscle store is well documented. For the head the evidence is inconsistent, and the largest study found no vegetarian specific advantage.
Carnosine and taurine: the honest correction
With carnosine I have to set a popular narrative straight. In the same study of 40 women, muscle carnosine did not change over six months, even though intake had stopped. What happens after ten years has not been studied.
With taurine the data rest on a 1988 paper with 12 vegan men. Plasma taurine was 45 instead of 58 µmol/l. Your body makes taurine from cysteine, so the value drops, but not to zero. A direction, not a clinical consequence.
The body can make it itself does not mean it makes the same amount in every situation in life.
Backup synthesis is a fallback level, not a full replacement. A lower level can stay unnoticed for a long time, because nothing breaks. Everything just gets a little tighter.
So much for the group that appears on almost no list.
When the precursor is not enough: vitamin A, vitamin D, EPA and DHA
Carrots contain vitamin A. You have heard that sentence a hundred times. It only holds with a footnote. Carrots contain beta-carotene, a precursor. To turn that into retinol your body needs the enzyme BCMO1, and it does not work at the same speed in everyone.
A European working group tested in cell culture, that is in vitro, how two common BCMO1 gene variants change enzyme activity, and then tested in volunteers.
The in vitro double mutant had 57% reduced activity. In the carriers, the ratio of retinyl palmitate to beta-carotene was 32% and 69% lower respectively. The group estimates the share of poor converters at up to 45%.
For you that means: for many, carrots are a good vitamin A source. For some clearly less so, without anyone being able to tell from the outside.
Leung WC et al. FASEB J. 2009. DOI: 10.1096/fj.08-121962 [In vitro and In vivo, human]A follow-up paper found three further variants that lowered activity by 48 to 59%, with allele frequencies between 19 and 100% depending on the population. Conversion capacity is not a constant of the species, it is a variable of ancestry. More on that in Genes, ancestry and metabolism.
With vitamin D the situation is more relaxed than often claimed. A meta-analysis of randomised head-to-head comparisons found that D3 raises the 25-OH level more than D2 does. With bolus dosing the gap was clear, with daily intake it disappeared. D2 comes from mushrooms, and vegan D3 from lichen exists too.
An Oxford team compared plasma fatty acids in 196 meat eaters, 231 vegetarians and 232 vegans in the United Kingdom.
EPA and DHA were lower in vegetarians and vegans. Crucially: the proportions did not depend on how long someone had eaten vegan, and that ranged from under one year to over twenty years. Plasma DHA was inversely correlated with linoleic acid.
For you that means: the body's own production from ALA appears to hold a low but stable level. Plenty of linoleic acid from vegetable oils appears to push DHA down further.
Rosell MS et al. Am J Clin Nutr. 2005. DOI: 10.1093/ajcn.82.2.327 [Cohort, n=659]The cascade from ALA via EPA to DHA is described in ALA, EPA, DHA and in Omega-3 from plants, animals or algae. Algae oil delivers both directly and purely plant based.
A precursor is a promise, not a delivery.
Beta-carotene is a promise of retinol, ALA one of DHA. Whether it is redeemed hangs on enzymes, and those differ between people. The same meal plan can lead to two very different blood panels.
That is why nutrient tables tell only half the story here.
Protein, leucine and bone: this is where it all comes together
A sentence I hear often: protein is not an issue, I eat lentils and tofu. Usually that is true. The catch often sits not in the amount, but in the composition.
A laboratory analysis of ten plant protein isolates shows the pattern. Oat, lupin and wheat contain 21 to 22% essential amino acids, whey 43%, milk 39%, egg 32%, human muscle protein 38%. Lysine and methionine are systematically lower. The solution sits in the same abstract: combinations of different plant proteins can come close to the animal profile.
For protein quality, DIAAS is considered more honest today than the older PDCAAS. It was measured in a pig model, not in humans. There the PDCAAS-style values were consistently higher, so the older method appears to systematically overestimate plant proteins.
Mathai JK et al. Br J Nutr. 2017. DOI: 10.1017/S0007114517000125 [In vivo, pig]It gets concrete with plant drinks. A Swiss analysis of 27 market products found that, apart from soy drinks, most contained 1% protein or less, with calculated DIAAS values clearly below cow's milk. The oat latte is not a milk substitute, it is a beverage. See also Dairy: healthy, poorly tolerated, or both.
At Maastricht University, 24 young men received 30 g of potato protein or 30 g of milk protein after single-leg resistance training, randomised and double blind, with muscle biopsies over five hours.
Both proteins raised the muscle protein synthesis rate clearly. Between the groups there was no difference, neither at rest nor in the trained leg.
For you that means: with a sufficient amount, plant protein can speak to muscle just as well. How many grams make sense is covered in How much protein do you really need.
Pinckaers PJM et al. Med Sci Sports Exerc. 2022. DOI: 10.1249/MSS.0000000000002937 [RCT, n=24]That leaves bone. Here protein quality, calcium, iodine, selenium and vitamin A show up together, and here sits the hardest number.
EPIC-Oxford followed 54,898 people for a mean of 17.6 years, among them 1,982 vegans, and recorded 3,941 fractures, 945 of them at the hip.
Compared with meat eaters, the hip fracture risk was a hazard ratio of 1.26 in fish eaters, 1.25 in vegetarians and 2.31 in vegans. In absolute terms that is 2.9, 2.9 and 14.9 additional cases per 1000 people over ten years. After adjustment for calcium and protein the association became weaker, but stayed significant.
For you that means: the absolute number puts the risk in a realistic frame. No reason to panic, but a good reason to keep bone in mind.
Tong TYN et al. BMC Med. 2020. DOI: 10.1186/s12916-020-01815-3 [Cohort, n=54,898]The German data show the same pattern. In 36 vegans, ultrasound values at the heel bone were lower. Of 28 biomarkers, twelve contributed most to the bone pattern, among them lysine, urinary iodine, TSH, selenoprotein P, vitamin A and leucine. A small cross-sectional study, so an observation.
Bone is not a calcium topic alone. It is a network topic. Lysine and leucine help build the collagen matrix, iodine and selenium steer the thyroid, and the thyroid helps steer bone remodelling. Looking only at calcium means seeing one thread in a fabric.
What well planned means in practice, and who it suits
One sentence appears in almost every text on this: a well planned vegan diet is possible. I sign it. I would just like us to finish the sentence. Because the load sits on those two words, well planned, and they are almost never explained.
The Academy of Nutrition and Dietetics, the large US professional body for dietitians, states: a well planned vegan diet can meet nutrient needs and is appropriate for all life stages, including pregnancy, breastfeeding, childhood and sport.
The German Nutrition Society weighs it more cautiously. For adults it considers a permanent B12 supplement, attention to critical nutrients and qualified dietary counselling necessary. For pregnant women, breastfeeding women, children and adolescents it does not recommend it.
Both positions are professionally grounded and deserve respect. They differ in how much planning effort they consider realistic in everyday life.
Where do I weigh things differently? First, I emphasise measuring more than planning. A plan is an intention, a lab value is feedback. Second, both lists leave out the group from section five: choline, creatine, retinol. That is my reasoned position, not the state of a guideline.
What belongs in regular testing
| What | Why this particular value |
|---|---|
| Methylmalonic acid or holo-transcobalamin | shows function, not just quantity |
| Homocysteine | second functional marker, also depends on folate |
| Ferritin plus transferrin saturation plus CRP | ferritin alone can be falsely reassuring during inflammation |
| 25-OH vitamin D | storage form, independent of D2 or D3 |
| Urinary iodine | the most frequently abnormal value in German data |
| Zinc | slowed by phytate, affected together with iron |
| Selenium or selenoprotein P | reflects status better than serum selenium |
| Omega-3 index | shows EPA and DHA in the membrane |
| Calcium and full blood count | the basis for bone and blood formation |
What belongs in supplementation: directions, not doses
- Vitamin B12 permanently. The point there is least argument about.
- Iodine worth keeping in mind, especially with a lot of cabbage and broccoli.
- Vitamin D according to the measured value, in winter almost always.
- EPA and DHA from algae oil, because your own production stays low.
- Iron and zinc often, but only after measuring.
- Choline worth keeping in mind for men and for women after menopause.
- Creatine as an option with strength training, inconsistent for cognition.
You will deliberately not find concrete amounts here. They depend on your values, your age and your medication. Below this article you will find the option to book an appointment.
Who it tends to suit, from my experience
It tends to suit people with stable digestion, access to diagnostics, a willingness to supplement permanently, without an extreme training load and outside special life stages. It gets harder with absorption disorders, inflammatory bowel disease, after stomach surgery, with a high training load and with a tendency to iron deficiency. BCMO1 variants belong on that list too.
Here I am deliberately cautious. The need is high, the stores are small, and gaps can later show up in places that are hard to turn back. In the review mentioned above, the B12 deficiency rate among pregnant vegetarians was 62%, and among children between 25 and 86%.
My position: if you want to live purely plant based in one of these life stages, then please not alone and not by gut feeling, but with medical and dietetic care and with close monitoring. That is not a ban, it is a request for company along the way.
The opposite pole is covered in The carnivore diet: what is behind it. The question of meat quality and processing, left out here, is covered in Meat and cancer: origin and processing.
Well planned is not the same as well meant. Well planned means: supplement, measure, adjust.
If you do that, a vegan diet is a well founded decision, and it can shift many markers in a favourable direction. If you do not, you are relying on stores that will be empty at some point. Both paths can look identical in the first years. After that, often not.
Common questions about vegan nutrition
Is a vegan diet healthy?
That depends less on the label than on the planning. In the EPIC-Oxford cohort, vegetarians and vegans had 22% less ischaemic heart disease, and in the same cohort 20% more strokes. In a twin RCT, LDL cholesterol fell by 13.9 mg/dl within eight weeks. At the same time, a few nutrients are hard to cover from plants alone. A well planned vegan diet can meet your needs. Well planned means something concrete here: supplement deliberately and have the right values measured regularly.
Which nutrients are most often missing on a vegan diet?
Vitamin B12 is the clearest case, because it is practically absent from purely plant food. Then come iodine, iron, zinc, selenium, vitamin D, calcium, plus EPA and DHA. Discussed less often, but just as relevant: choline, creatine and vitamin A in the form of retinol. In a German study by the Federal Institute for Risk Assessment, one third of the vegans excreted less iodine than the WHO threshold for severe iodine deficiency.
What are the first symptoms of a deficiency on a vegan diet?
The early signs are unspecific: tiredness, trouble concentrating, tingling in hands or feet, hair loss, breathlessness on exertion, feeling cold, frequent infections. That is exactly why they often go unnoticed for years. With vitamin B12, neurological signs can even appear before anaemia does. Symptoms are a good reason to measure, but they are not a diagnosis.
My vitamin B12 value is normal, can I still have a deficiency?
Yes, that is possible. Around 80% of serum B12 is bound to haptocorrin and is not available to your cells. Only 6 to 20% is bound to transcobalamin, and that is the metabolically active fraction. Methylmalonic acid and homocysteine, by contrast, show whether the B12 dependent enzymes are actually working. The combination of holo-transcobalamin and methylmalonic acid is considered more informative than total B12 alone.
Which blood values should I have checked regularly as a vegan?
Useful ones are: methylmalonic acid or holo-transcobalamin instead of serum B12 alone, homocysteine, ferritin together with transferrin saturation and CRP, 25-OH vitamin D, urinary iodine, zinc, selenium or selenoprotein P, calcium, the omega-3 index and a full blood count. Which of these make sense for you, and at what interval, depends on age, life stage, training load and history, and belongs in a conversation with your doctor.
How long does it take for a B12 deficiency to show up on a vegan diet?
The liver stores vitamin B12 for years. That is why the switch feels completely uneventful at first. In a systematic review of 18 studies, deficiency rates ranged from 11 to 90% depending on the group, with particularly high values in pregnant women and children. People who had been vegetarian since birth were affected more often than those who switched later.
Do vegans really need creatine?
The muscle store is measurably lower on a purely plant based diet, and it can be refilled. For cognition the picture is mixed. A small study from 2003 found clear effects in vegetarians, while the largest and preregistered study so far, from 2023 with 123 participants, found no vegetarian specific advantage. A systematic review found no effect on phosphocreatine in the brain. So the muscle store is well documented, the head is not.
Do I need to supplement taurine as a vegan?
There is no solid basis for that so far. The data rest on a 1988 paper with 12 vegan men, in which plasma taurine was 45 instead of 58 µmol/l. Your body makes taurine from cysteine itself, so the value drops, but not to zero. That shows a direction, not a clinical consequence. The evidence is too thin for a recommendation.
Is beta-carotene from carrots enough as a vitamin A source?
For many people yes, for some clearly less so. Beta-carotene first has to be converted into retinol by the enzyme BCMO1. Common gene variants lowered the activity of this enzyme by 48 to 59% in studies, and the authors estimate the share of poor converters in the population at up to 45%. How common these variants are differs strongly by geographic ancestry.
Is a vegan diet bad for your bones?
The data give a signal that deserves to be taken seriously. In the EPIC-Oxford cohort of 54,898 people, the hip fracture risk in vegans came to a hazard ratio of 2.31. In absolute numbers that is 14.9 additional cases per 1000 people over ten years. The association remained after adjustment for BMI, calcium and protein, although weaker. German ultrasound data show the same pattern, and there lysine, leucine, iodine, selenium and vitamin A appear in the bone pattern alongside calcium.
Do I get enough protein for building muscle as a vegan?
That can work, but it needs more attention to amount and combination. Plant proteins contain on average 21 to 22% essential amino acids compared with 32 to 43% in animal proteins, and lysine and methionine are systematically lower. In an RCT with 24 young men, 30 g of potato protein stimulated muscle protein synthesis just as strongly as 30 g of milk protein. So the plant is not the obstacle. Amount and amino acid combination are.
Is a vegan diet suitable for children and during pregnancy?
This is where the professional bodies part ways. The Academy of Nutrition and Dietetics considers a well planned vegan diet appropriate for all life stages, including pregnancy, breastfeeding and childhood. The German Nutrition Society does not recommend it for pregnant women, breastfeeding women, infants, children and adolescents. In a systematic review, the B12 deficiency rate among pregnant vegetarians was 62%. In these life stages, a purely plant based diet belongs in medical and dietetic care in my view, with close monitoring.
Where this topic leads next
Iodine leads to the thyroid, zinc to the hormones, the omega-3 index to measurement methods, the cofactor question to energy inside the cell. From here, paths lead into other areas.
Measuring the omega-3 index
The blood value that shows EPA and DHA in the membrane
MeasureThyroid despite normal values
Why TSH alone does not answer the iodine and selenium question
Zinc, vitamin D, testosterone
What trace elements can move in the hormone system
Burnout, gut, mitochondria
When energy is missing and the cofactors are scarce
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- The carnosine narrative is more popular than its evidence. The only prospective study found no change over six months. What happens after ten years is unknown.
- Taurine rests on a 1988 paper with 12 men. A direction, not a clinical consequence.
- On creatine and cognition the studies contradict each other. What is documented is the lower muscle store and that it can be refilled. Phosphocreatine in the brain did not change.
- An anti-inflammatory advantage did not show up in the German data. The correlation with vegan duration comes from n=72 and is far from proof of causation.
- The link between vegan eating and choline deficiency is a plausible inference. The depletion study was not carried out in vegans, and the intake survey comes from the USA.
- The microbiome advantage rests here on a narrative review from an author group with a plant based orientation. The direction is supported, the source is not neutral.
- The idea that B12 status helps explain the fracture rate is mechanistically plausible, but comes from a hypothesis paper. Human data on it are missing.
- The DIAAS numbers come once from a pig model and once from calculations, not from measurements in humans.
- The stroke signal in EPIC-Oxford is statistically robust, and the mechanism behind it is unexplained to this day. That is why I leave it standing as an open question.