I have a few more questions about your article. Again, I appreciate your response.

You stated twice that “vitamin D levels are 74% lower in vegans than in meat eaters,” citing Winston John Craig’s 2010 article “Nutrition Concerns and Health Effects of Vegetarian Diets.” I am curious where you found those statistics in that article. I have the article in front of me and I cannot find it. I only see that it says that vitamin D status can be “compromised in some vegans” and that vitamin D deficiency was reported in vegan groups that did supplement or consume fortified foods.

Could you perhaps have been referring to the 2011 EPIC-Oxford Study? Here is a quote from the study. “Although the vegans had lower vitamin D levels than did meat-eaters, their vitamin D levels would be considered in the healthy range of 50 to 125 nmol/l according to the Institute of Medicine. The researchers noted that the average vitamin D levels in vegans were “comparable, if not slightly higher, than that reported in other studies among the general British population,” although this could be due to differences in the measurement method. The researchers surmised that the lower calcium intake in vegans may have lowered their vitamin D levels further because more 25(OH)D would be converted into the active vitamin D hormone to increase calcium absorption.”

You also claimed that a low-fat diet is associated with vitamin D deficiency. Aside from the fact that vegan and vegetarian diets are often high in fat and full of nut butter, coconut oil, and olive oil, I cannot find a credible connection between a low-fat diet and vitamin D deficiency. It is well known that oral vitamin D supplements are absorbed better when taken with a meal containing fat. However, vitamin D from sunlight is synthesized from natural oils in the skin and is not connected to dietary fat intake. In fact, a study from the Netherlands found that lower vitamin D levels in the general population are associated in women with abdominal fat and in men with fatty liver. Also, people who have issues absorbing fat will have issues absorbing fat-soluble vitamins. A 2009 study in the American Journal of Clinical Nutrition found that skin pigmentation and sun exposure had more significant effects on vitamin D status than did a diet.

In a brand new study from UC San Diego, researchers found that gut bacteria may play a crucial role in converting vitamin D to its active form. They found that active vitamin D levels correlated with the diversity of the community of bacteria. And even though more research is needed, they think that the ability to metabolize vitamin D may be more important than how much vitamin D you get through supplements or the sun.

You also wrote that “research suggests that our bodies tan, in part, to protect against vitamin D toxicity.” As far as I understand, our bodies do not tan to protect against vitamin D toxicity, our bodies regulate vitamin D production through sun exposure. What research are you referring to? I am curious.

“Thyroid-Gut-Axis: How Does the Microbiota Influence Thyroid Function?” is an interesting article, published in Nutrients in 2020, that analyzes the relationship between thyroid function, intestinal health, and the gut microbiome. I would argue that the most recent research, including the Sonnenburg studies I mentioned in my last comment, suggests that the problematic symptoms people experience on vegan, vegetarian, and plant-based diets may be rooted in a perturbed and depleted microbiome that is dysfunctional and unable to process plant fibers. And this explains why so many people feel better on a keto or carnivore diet. As Justin Sonnenburg said, these diets can act like antibiotics in the gut because they limit the amount of fuel the bacteria can access. These diets can alleviate unwanted symptoms but they don’t fix the root of the problem which is a depleted microbiome.

FYI I am at home with Covid, not too sick but with enough time on my hands to really look into the details of your article. I appreciate you taking the time to respond. Thank you.

We know that multiple studies have confirmed that B12 deficiency can be caused by genetic factors, age, and intestinal malabsorption. Vegans and vegetarians know to supplement with B12, as most of us should because some meat eaters are at risk as well. Everyone should have their vitamin D levels checked regardless of what diet they eat. I don’t know of anyone that would recommend relying on animal protein to reach adequate levels of vitamin D. Risk factors for low vitamin D include having dark skin, being older or overweight, and having malabsorption issues to name a few.

Another important consideration is soy and cruciferous vegetables. All of the most recent research has concluded that, in regular amounts, soy and cruciferous veggies do not slow the thyroid. A group that ate the highest amount of soy products only had a small and insignificant reduction in thyroid hormone. There has only been one isolated case of an elderly woman juicing pounds of cabbage a day that can be attributed to cruciferous veggies causing hypothyroidism. Both whole, organic soy and cruciferous veggies are associated with lower rates of cancer and lower inflammation.

The last consideration is phytates, which work as an antioxidant in the colon and have been shown to be protective against colon cancer. There was an extensive meta-analysis on the Mediterranean diet, which is very high in phytates, that showed zero correlation between phytic acid and nutrient deficiency. And this has been shown again and again in populations that are not starving. Yet so-called nutrition ‘gurus’ continue to cite inconclusive studies that were done on impoverished and resource-poor demographics to make the claim that phytates should be avoided. It is honestly, in my opinion, irresponsible given the fact that colon cancer is the third leading cause of cancer deaths in the US.

Have you seen the recent studies by the Sonnenburg Lab at Stanford? They found that a high fiber diet resulted in 2 distinct reactions. One group increased microbiome diversity and had lowered inflammatory markers. The second group’s microbiome did not diversify and they had increased inflammatory markers. What they found in the second group is that their microbiome was depleted to begin with. Another study they did found that low fiber diets in mice resulted in depleted microbiomes. And over several generations, adding fiber back into the diet could not replenish the microbiome because the mice had lost the bacteria that break down fiber. When bacteria break down fiber, they make short-chain fatty acids, which are the marker of health in the human body.

The largest microbiome study by the American Gut Project found that Americans have some of the most depleted microbiomes in the world. Many Americans have lost the bacteria that break down fiber. They have also lost bacteria that protect against SIBO and other digestive issues. And like the results of the most recent Sonnenburg study, these people may experience increased inflammation and digestive distress when switching to a whole-food plant-based diet. I suspect that this is at the root of why vegan diets cause problems for some people and not for others.

There is also evidence to suggest that we can regrow the diversity in our microbiome. It involves introducing fiber-rich foods in small quantities that don’t cause problematic symptoms. For example, eating one tablespoon of black beans once a day can give beneficial bacteria a chance to regrow. When certain people who are sensitive eat too many black beans at once, the result can be an overgrowth of problematic bacteria – bacteria that would otherwise be kept in check by a diverse microbiome.

I am very curious to know your reasoning behind why a vegan diet could potentially cause hypothyroidism. Thank you for your response.

Hey Kendra,

Thanks for your comments. For what it’s worth, I agree with you that this article is in serious need of refinement. It was originally posted in 2016 and it hasn’t gone any major updates or scientific review since its original publication. Over the past six years, as I became more involved in research and medical editing, the quality of our articles improved greatly. Unfortunately, there are a few articles in our backlogs that don’t really reflect the level of discernment that we hold today for any interventions. This is one of them, and you’re right to criticize it.

I will say that I’ve tried several bouts of vegetarianism and veganism, and after so much personal experimentation, I’m fully convinced that it isn’t the right diet for me. Having said that, I also recognize that some people who are vegans are absolutely thriving. But without better data, it’s not right of me to project my anecdotal experience as a rationale for why vegan diets won’t regrow hair lost due to androgenic alopecia.

For what it’s worth, I still stand by the messaging within the article: that vegan diets can often push people toward hypothyroidism, and that in certain cases, vegan diets can exacerbate telogen effluvium-related sheds. But I also feel the same can occur with ketogenic diets, especially when weight loss is a primary goal.So, as you eluded to, there are a lot of ways to incorrectly do any diet – vegan or otherwise.

Perhaps you might enjoy this article, as it is a bit more updated and reflective of my current opinions: https://perfecthairhealth.com/best-diet-hair-loss/

Thanks again and feel free to comment any time. Your comments – moving forward – should be automatically approved.

Best,
Rob

I also think it’s interesting that you titled the article with a claim based on your anecdotal experience. Usually, you title your articles in a scientific way that creates an inquiry for potential readers. You don’t even need to read this article to know exactly what conclusions will be made. And you are making claims for others based on your experience alone. It is disappointing. I am not vegan, I just care about science and evidence.

Hey Lily,

Thanks for sharing your story, and thank you for reaching out about this. As you mentioned, it sounds like there are a lot of factors going on that might be contributing to your hair shedding / hair thinning. It’s tough for me to provide directional insights here without knowing a bit more about you, so please feel free to give me a call (the number at the bottom of the site) so that we can connect, I can ask a few more questions, and hopefully you can formulate an action plan.

The quick answer: when there are multiple suspected causes involved, someone almost always needs to do a full health evaluation and receive a hair loss diagnosis by a qualified dermatologist. If the latter isn’t available, there are some resources you can access to do this yourself. As far as working with vegans as they pursue options outside of dietary changes to improve their hair – it’s entirely possible to do this; it just takes a lot of experimentation. But that experimentation can work both ways. For instance, some people will find that the autoimmune reactions you’ve described are evident with red meat, but not after eating chicken and/or seafood.

Best,
Rob

A few years ago, I developed some kind of inflammatory/autoimmune arthritis (similar to psoriatic arthritis in terms of the type/pattern of joint issues, but without the psoriasis). About 5 months ago, in desperation, I started a strict “whole-foods plant-based” diet that is promoted as helping to manage or heal similar conditions. The diet is very strict (in addition to eliminating all animal products, it eliminates all added oils — with fats instead being provided by large amounts of flax, chia, avocado, etc.). Although I was very pessimistic, I was surprised to find that a 90% improvement in joint pain/tenderness and other symptoms. I felt almost normal for the first time in 3 years, and I thought that maybe this annoyingly strict diet was the answer.

Around the time I first noticed the autoimmune issues (about 3 years ago), my once thick and shiny hair (typical Asian hair) began shedding much more than usual, and about 6 months ago I noticed that my hair was half the volume it used to be. The shedding unfortunately seems to have gotten worse since I started the strict vegan diet (about 5 months ago). My ferritin and zinc levels have always been on the low side, so I recently started to take supplements for that. A few weeks ago, after freaking out slightly about how thin my hair has become, I started taking some grass-fed collagen, beef liver supplements, and Omega 3 supplements — on the assumption that (i) I needed more protein and fat and (ii) needed things like lysine to help me absorb iron. However, just those few weeks of ingesting animal proteins have caused the autoimmune arthritis to flare up dramatically.

I now find myself feeling like I have to choose between (i) being in pain (and suffering permanent joint damage), and (ii) continuing to lose hair, which is honestly (and pathetically) almost as devastating as the joint pain.

I know there are a lot of factors at play. I’m 47, so probably in peri-menopause, and fluctuating hormones are probably contributing both to the development of the autoimmune issues and to the hair loss. So maybe it’s not as simple as “eat animal products to get your hair back,” or “eliminate animal products to stop the joint pain.” But it would be so helpful to know if, in your experience with your many readers, people on strict vegetarian diets are ever able to arrest hair loss. Thank you so much — sorry to be so long-winded.

cant you just do a vegan keto diet and supplement with vit d3 and pea protein.
(ive been vegan for 3 years now and started shedding/losing hair 3 months into it, so i just recently started keto d3 supplemnt/k2)

how long did it take your hair to regrow after you stopped being vegan?