Jack Norris RD

I have changed my vitamin B12 recommendations.

A 2010 paper by Bor et al., showed that in healthy people aged 18-50, a vitamin B12 intake of 4 to 7 mcg/day was associated with the lowest methylmalonic acid and homocysteine levels (1). They reviewed other research from the past 10 years, primarily on older populations, that reinforces this finding.

My previous recommendations were 1.5 – 2.5 µg twice per day. I have changed that to 2.0 to 3.5 µg twice per day. For supplements, I raised the lower end of the range from 10 µg to 25 µg. The daily range is now 25 to 100 µg.

You can read an explanation of my recommendations here under Step 2.

1. Bor MV, von Castel-Roberts KM, Kauwell GP, Stabler SP, Allen RH, Maneval DR, Bailey LB, Nexo E. Daily intake of 4 to 7 microg dietary vitamin B-12 is associated with steady concentrations of vitamin B-12-related biomarkers in a healthy young population. Am J Clin Nutr. 2010 Mar;91(3):571-7.

[I originally posted this a few days ago and then discovered I was having problems with my RSS feed. I now have a temporary solution, but I think if you chose to get the feed via email, it won't work. If you do get the feed via email (you will know this if you don't have a separate folder for my blog) and this shows up, please let me know at b12303@google.com. Thanks!]

A couple days ago, someone posted to the SFBAVeg email list that they saw some white mushrooms in Safeway advertised as having 100% RDA for vitamin D. I was aware that some mushrooms had small amounts of vitamin D2 in them, but 100% of the RDA (5 mcg / 200 IU) was a surprise.

A follow up post linked to the article Light-zapped mushrooms filled with vitamin D, from 2006, which reported a study being conducted measuring the levels of vitamin D2 in mushrooms exposed to ultraviolet (UV) rays. I then went to PubMed and found a few abstracts (listed below) of completed studies indicating that exposing mushrooms to vitamin D2 does increase their vitamin D content.

I’m not sure what the exact content of vitamin D in such mushrooms tends to be, but if it is about the RDA per serving, then one serving is still far short of the 25 mcg (1,000 IU) that recent research indicates might be needed for optimal health (for people not getting much sunlight). That said, eating UV treated mushrooms could be a big boost.

More info on vitamin D.

Ko JA, Lee BH, Lee JS, Park HJ. Effect of UV-B exposure on the concentration of vitamin D2 in sliced shiitake mushroom (Lentinus edodes) and white button mushroom (Agaricus bisporus). J Agric Food Chem. 2008 May 28;56(10):3671-4. Epub 2008 Apr 29.

Koyyalamudi SR, Jeong SC, Song CH, Cho KY, Pang G. Vitamin D2 formation and bioavailability from Agaricus bisporus button mushrooms treated with ultraviolet irradiation. J Agric Food Chem. 2009 Apr 22;57(8):3351-5.

I am currently having problems with my RSS feed. I am working to get it fixed as soon as possible.

[It doesn't seem like any subscribers got this post, so I'm trying it again.]

A couple days ago, someone posted to the SFBAVeg email list that they saw some white mushrooms in Safeway advertised as having 100% RDA for vitamin D. I was aware that some mushrooms had small amounts of vitamin D2 in them, but 100% of the RDA (5 mcg / 200 IU) was a surprise.

A follow up post linked to the article Light-zapped mushrooms filled with vitamin D, from 2006, which reported a study being conducted measuring the levels of vitamin D2 in mushrooms exposed to ultraviolet (UV) rays. I then went to PubMed and found a few abstracts (listed below) of completed studies indicating that exposing mushrooms to vitamin D2 does increase their vitamin D content.

I’m not sure what the exact content of vitamin D in such mushrooms tends to be, but if it is about the RDA per serving, then one serving is still far short of the 25 mcg (1,000 IU) that recent research indicates might be needed for optimal health (for people not getting much sunlight). That said, eating UV treated mushrooms could be a big boost.

More info on vitamin D.

Ko JA, Lee BH, Lee JS, Park HJ. Effect of UV-B exposure on the concentration of vitamin D2 in sliced shiitake mushroom (Lentinus edodes) and white button mushroom (Agaricus bisporus). J Agric Food Chem. 2008 May 28;56(10):3671-4. Epub 2008 Apr 29.

Koyyalamudi SR, Jeong SC, Song CH, Cho KY, Pang G. Vitamin D2 formation and bioavailability from Agaricus bisporus button mushrooms treated with ultraviolet irradiation. J Agric Food Chem. 2009 Apr 22;57(8):3351-5.

As foods go, eggs are very high in cholesterol. Back when it was thought that eating cholesterol caused an increase in blood cholesterol, people with high cholesterol or heart disease were warned away from eggs. But then it was found that while some people’s cholesterol levels rise significantly from eating cholesterol, most people’s do not. So where does that leave eggs?

The findings have been somewhat mixed over the years. The most recent paper I found was a 2008 report from the Physicians’ Health Study (a trial to study low dose aspirin and beta-carotene’s effects on the primary prevention of cardiovascular disease and cancer among US male physicians) (1). They found the following when comparing consumption of 7+ eggs per week to less than 1 per week:

• No correlation with stroke or heart attacks
• A 23% increased risk of mortality (1.23, 1.11-1.36)
• A doubled risk of mortality among men with type 2 diabetes (2.01, 1.26-3.20)

These results were adjusted for age, body mass index, smoking, hypertension, vitamin intake, alcohol consumption, vegetable consumption, breakfast cereal consumption, physical activity, treatment group, atrial fibrillation, diabetes mellitus, hypercholesterolemia, and parental history of premature myocardial infarction.

The authors of this paper reviewed the previous literature on eggs and mortality:

“Limited and inconsistent data have been reported on the association between egg consumption and coronary heart disease. Among 514 Australian Aborigines, consumption of 2+ eggs per week was associated with a 2.6-fold increased risk of coronary heart disease in a prospective analysis (2). Mann et al. (3) reported a 2.7-fold increased risk of death with a higher egg consumption (6+ per week) among British subjects. In contrast, other large prospective cohorts with longer follow-ups did not observe any association between egg consumption and CHD or mortality (4-7).”

They discussed other research showing 7+ eggs increased the risk of heart disease in men and women with diabetes (5).

In conclusion, it appears that in comparison to less than one egg per week, eating 7+ egg per week could increase your risk of early death, especially if you have type 2 diabetes.

References

1. Djousse L, Gaziano JM. Egg consumption in relation to cardiovascular disease and mortality: the Physicians’ Health Study. Am J Clin Nutr. 2008 Apr;87(4):964-9.

2. Burke V, Zhao Y, Lee AH, et al. Health-related behaviours as predictors of mortality and morbidity in Australian Aborigines. Prev Med 2007;44:135–42. [PubMed: 17069878]

3. Mann JI, Appleby PN, Key TJ, Thorogood M. Dietary determinants of ischaemic heart disease in health conscious individuals. Heart 1997;78:450–5. [PubMed: 9415002]

4. Dawber TR, Nickerson RJ, Brand FN, Pool J. Eggs, serum cholesterol, and coronary heart disease. Am J Clin Nutr 1982;36:617–25. [PubMed: 7124663]

5. Hu FB, Stampfer MJ, Rimm EB, et al. A prospective study of egg consumption and risk of cardiovascular disease in men and women. JAMA 1999;281:1387–94. [PubMed: 10217054]

6. Nakamura Y, Okamura T, Tamaki S, et al. Egg consumption, serum cholesterol, and cause-specific and all-cause mortality: the National Integrated Project for Prospective Observation of Noncommunicable Disease and Its Trends in the Aged, 1980 (NIPPON DATA80). Am J Clin Nutr 2004;80:58–63. [PubMed: 15213028]

7. Nakamura Y, Iso H, Kita Y, et al. Egg consumption, serum total cholesterol concentrations and coronary heart disease incidence: Japan Public Health Center-based prospective study. Br J Nutr 2006;96:921–8. [PubMed: 17092383]

I just updated VeganHealth.org’s articles on bones and homocysteine with the following:

Vitamin B12 and Bone Mineral Density

Taking vitamin B12 might also be important for bone mineral density.

A 2009 cross-sectional study of lacto-ovo vegetarian women in Slovakia found that their higher homocysteine (16.5 vs. 12.5 µmol/l; 78% vs. 45% were elevated) and lower vitamin B12 levels (246 vs. 302 pmol/l; 47% vs. 28% were deficient) were associated with significantly lower bone mineral density in the femur (1). Participants were not allowed to have been taking vitamin or mineral supplements. The researchers did not measure calcium intake or vitamin D status.

You can read more about vitamin B12 and homocysteine here.

1. Krivosikova Z, Krajcovicova-Kudlackova M, Spustova V, Stefikova K, Valachovicova M, Blazicek P, Nemcova T. The association between high plasma
homocysteine levels and lower bone mineral density in Slovak women: the impact of vegetarian diet. Eur J Nutr. 2009 Oct 7.

I just updated Another Internet Soy Article with the following:

A 2009 report from the Shanghai Breast Cancer Survival Study showed that women with a prior diagnosis of breast cancer (including estrogen-positive), who ate more soy, had lower rates of death and cancer recurrence (12). The study followed women for an average of 3.9 years after a diagnosis of breast cancer. The researchers measured a beneficial effect of up to 11 grams of soy protein per day. Table 3 shows the results.

12. Shu XO, Zheng Y, Cai H, Gu K, Chen Z, Zheng W, Lu W. Soy food intake and breast cancer survival. JAMA. 2009 Dec 9;302(22):2437-43.

After the posts I made regarding the article, A Whole Diet Approach to Building Better Bones, in the Vegetarian Voice, two people contacted me to say that the World Health Organization recommends more than the 400 to 500 mg of calcium per day as stated in the article. According to Table 4.2 on p. 71 in their document, Vitamin and Mineral Requirements in Human Nutrition, Second Edition (2004), the WHO recommends:

1,300 mg for ages 10 to 18
1,000 mg for women 19 to menopause
1,300 mg for women past menopause
1,000 mg for men 19 to 65
1,300 mg for men ages 65+

And if you missed them, there have been many comments in response to these two posts (link, link).

Erik Marcus of Vegan.com has just posted his latest writing, The Year in Meat: 2009. No one bashes the meat industry more eloquently than Erik!

Today, Vegan Outreach unveiled a slideshow to share with everyone what we accomplished in 2009. You can see it by clicking here.

It will soon be too late to get a tax deduction for a year-end donation to Vegan Outreach! Our end-of-year fundraising determines most of what we will be able to accomplish during the winter and spring school semesters. The more donations we have, the more students we reach.

In addition to being part of giving a hard-hitting booklet to almost 1 million students a year about how animals are treated on modern farms, a donation to Vegan Outreach indirectly supports much of the nutrition information you get here by way of the work I do maintaining VeganHealth.org. Not many organizations would support public, no-holds-barred discussions of vegan nutrition, but we believe these candid discussions can only help reduce animal suffering in the end.

Thank you for anything you can give!

You can donate to Vegan Outreach here.

Happy New Year!

Jack Norris, RD