It’s just not possible for dietitians to be knowledgeable about every single aspect of nutrition. If you put me in charge of a dialysis unit, I’m sure all the patients would be dead in no time at all. Although I took a few clinical nutrition courses in school, I learned—and promptly forgot—just enough to pass my RD exam.
So, I wouldn’t take a job as a hospital dietitian and I wouldn’t agree to do an interview on any aspect of clinical nutrition. Unfortunately, when it comes to vegan (and vegetarian) diets, journalists often end up interviewing health professionals who don’t have expertise in this particular area. It often results in misinformation and sometimes exaggerates the potential pitfalls of vegan diets.
In this article in the Springfield, Missouri News-Leader, a dietitian suggested that vegetarians can be at risk for not getting enough protein, vitamin B12, calcium, zinc, iron, and vitamin D. The symptoms that could result from this were frightening indeed and included osteoporosis, muscle wasting and tongue deformities. (I have to say—the tongue deformity thing was new to me.)
Some points in response to that article, particularly in regard to vegan diets:
- It’s true that vegans need to pay attention to vitamin B12. But I’ve written before about why I think vegans could actually have an advantage over omnivores regarding this nutrient, especially as they age.
- Vegans have higher iron needs than meat-eaters, but they do not have higher rates of iron-deficiency anemia. And vegans have a distinct advantage over those vegetarians who consume dairy products since dairy is devoid of iron and interferes with its absorption.
- Lacto-ovo vegetarians, vegans and meat eaters all get vitamin D in exactly the same ways—from sun exposure or fortified foods. (Milk is not a natural source of vitamin D; it’s fortified with it.)
- There is a little bit of a learning curve regarding calcium for vegans, but it is certainly not difficult to get enough. There is no disadvantage to getting calcium from plant foods or fortified foods and there may be some advantages.
- Vegans have slightly higher protein requirements than omnivores but those needs are met with ease. When people eat a variety of plant foods and get enough calories, protein deficiency is pretty unlikely.
- Zinc is a tricky issue. There is so much we don’t know about this nutrient as it relates to marginal deficiencies. It’s found in nuts, seeds, legumes and whole grains, but I’m increasingly inclined to recommend that vegans supplement with zinc just to be on the safe side. I’m fairly cautious about these issues, though, and we absolutely do not see overt zinc deficiency in the vegan population.
Finally, the News-Leader article stated rather emphatically that vegan children will grow more slowly than omnivores and that growth will be in the “low-normal” category. That seems like an over-statement to me. Given the lack of good data on this issue, I don’t think we can predict the growth of vegan children one way or the other. There are a few studies showing that vegan children grow more gradually than meat-eaters, but that they attain similar heights by puberty. These are older studies, however. It would be more instructive to look at growth in today’s vegan kids, given the much greater availability of good nutrition information for vegans as well as the increased availability of protein- and calorie-rich vegan foods.
But there is a more important question. Is more gradual growth a sign that vegan diets are inferior? We can look to the growth of infants in omnivore families for some answers. While breastfeeding is the gold standard for infant feeding, breast fed infants grow more slowly than those who are fed formula. This tells us that the faster growth of bottle fed babies is not normal and is most likely not ideal. So, if it turns out that omnivore kids grow faster than vegans, who is to say that this is advantageous?
We may not know the answer to that, but we do know that vegan diets can provide everything that children need to meet nutrient needs, grow well, and attain normal heights. And if you don’t believe me, take a look at these beautiful vegan kids!