I was hoping this day would never come – the day that I had to admit there might be some potential side effects to vitamin B12 supplements!

I have heard from a few people over the years that they had a reaction to vitamin B12 supplements. In those cases, it was not clear whether it was the actual vitamin B12 or possibly another chemical that was included in the supplement preparation.

But in June of 2010, someone wrote me saying that there had been some discussion on a German Blog that several people started getting “bad” skin after taking b12 supplements. As I am not a reader of German, I noted it but did not research further.

Then, on October 27, someone commented on the Will a Multivitamin Cover B12 Needs? post, saying they had developed acne after supplementing with vitamin B12.

I did some more research and found some cases in the scientific literature in which vitamin B6 and/or vitamin B12 was thought to be the cause of acne and rosacea. I have added the page Side Effects of B12 Supplements to Vitamin B12: Are You Getting It? in order to alert people to this possibility.

It would be good to know what sort of dose could typically cause this problem, how much of a culprit vitamin B12 is compared to vitamin B6, and if all forms of vitamin B12 are implicated. I found very little on it and the most recent report was from 2001, so it is not an area of much study at this point.

Of course, if you suspect high doses of vitamin B12 to be causing a problem for you, opt for smaller doses more often (see Recommendations).

A paper has just been published in Advances in Food and Nutrition Research that claims seaweeds are a good source of vitamin B12 for vegans (1). The author does not provide any new information, but rather relies on a number of studies that have measured the B12 analogue content of various seaweeds (see B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods for an analysis of these studies).

To date, no study has shown any seaweed to improve vitamin B12 status, although two studies showed that spirulina (2) and nori (2, 3) were not able to do so. So it is rather premature, to say the least, to say that any seaweed is a “good” source of vitamin B12, and unfortunate that someone would publish that opinion in a peer-reviewed journal.

References

1. Skrovánková S. Seaweed vitamins as nutraceuticals. Adv Food Nutr Res. 2011;64:357-69.   |   Link

2. Dagnelie PC, van Staveren WA, van den Berg H. Vitamin B-12 from algae appears not to be bioavailable. Am J Clin Nutr. 1991;53:695-7.   |   Link

3. Yamada K, Yamada Y, Fukuda M, Yamada S. Bioavailability of dried asakusanori (porphyra tenera) as a source of Cobalamin (Vitamin B12). Int J Vitam Nutr Res. 1999 Nov;69(6):412-8. Yamada K, Yamada Y, Fukuda M, Yamada S. Bioavailability of dried asakusanori (porphyra tenera) as a source of Cobalamin (Vitamin B12). Int J Vitam Nutr Res. 1999 Nov;69(6):412-8.   |   Link

Can you get a blood test to determine if you have enough iodine in your system?

No, there is no common test to determine how much iodine you have in your body. The American Thyroid Association discusses this in their article Iodine Deficiency.

I added a link to that article from the Iodine page on VeganHealth.org.

If you have no idea if you get enough iodine, please check out the links!

Meet Jack, A Vegan Advocate for Life

Dr. Michael Greger’s Latest in Clinical Nutrition 6 is now available! In it, he mentions a study about taking vitamin D with meals. I’ve wondered if doing this would help people whose vitamin D levels seem to be resistant to supplementation and so I tracked down the study and updated the VeganHealth.org article, Bones, Vitamin D, and Calcium:

Because vitamin D is a fat soluble vitamin, taking vitamin D supplements with foods that contain fat might increase absorption.

A 2010 study explored this (1). A group of people diagnosed with vitamin D deficiency had been prescribed supplements (some D2 and some D3) and were being monitored by the Cleveland Clinic Foundation Bone Clinic. Some of these patients’ vitamin D levels had not increased to desired levels. Patients with stubborn vitamin D levels were then instructed to take the vitamin D with meals. After 2 to 3 months of taking with meals, the average vitamin D level went from 30 to 47 ng/ml (75 to 117 nmol/l).

This study had no control group, so it is not clear that the vitamin D levels increased due to taking with meals. It could have been simply because their levels took longer to respond to supplements or because they were exposed to more sunlight during the meal period (the time of year studied was not reported). It should also be noted that even though these subjects’ vitamin D levels were more stubborn than other patients, their levels at the beginning of the study were well above those recommended by the Institute of Medicine (16-20 ng/ml or 40-50 nmol/l) the stubborn levels might have been a result of the body regulating vitamin D once it had reached an ideal level rather than an inability to absorb it.

Reference

1. Mulligan GB, Licata A. Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D. J Bone Miner Res. 2010 Apr;25(4):928-30. Link

Reed Mangels, PhD, RD is probably the world’s foremost expert on nutrition for vegan pregnancies. She has just written a new book, The Everything Vegan Pregnancy Book. Ginny Messina reviews it here.

I have added a page of nutrition calculators to PeaCounter.com.

Readers of my blog might be particularly interested in the Body Mass Index, Ideal Body Weight, and vitamin D calculators.

If you have any conversions you use regularly and would like to see there, please let me know here.

Dr. Michael Greger is quoted in this Chicago Tribute article from yesterday about eating for your blood type: Should blood type guide your food choices?

Even after 15 years, Dr. Michael Klaper’s article on the blood type diet is still, to my knowledge, the best response to it:

Challenges to the Plant-Based Diet in the 90’s: “The Zone” and “Blood-Type” Diet Fads

The Mayo Clinic in Phoenix is looking for vegans, 40 years an older, in the area to study. You will need to donate a blood sample and will be compensated $25.

Call Patsy Thrush if interested: 480-301-4981

I was able to attend a screening of Vegucated last night in San Francisco and I highly recommend that you take your non-veg friends to see it if you get a chance.

Marisa Miller Wolfson is the filmmaker and the movie begins with a brief synopsis about her journey to becoming vegan. The main part of the movie, though, is about three New Yorkers who she finds via Craigslist and persuades to give veganism a try for six weeks. She takes them through a process of “vegucation” which mainly includes teaching them about how animals are treated, about some of the health benefits of eating a plant-based diet, and how to make the transition.

Most of the filming was done around 2006 so a lot of time has now passed since the 6-week challenge and 2 of the 3 people are still vegan (in fact, one of them attended the screening last night).

Vegucated is fun (except for relatively short sections on animal farming) and I think it would be very hard to walk away from it without having some significant interest in veganism and a positive view of vegans and how we are trying to make the world a better place.

Currently, the only way to see the film is to attend a screening (dates and locations). There is one in Sacramento tonight (October 26, 2011) at 6:30.

You can also host a screening in your area starting in January (more info).