Vitamin D3 Performs Slightly Better Than D2 in Clinical Trial

June 23rd, 2015 by Jack Norris RD

I have updated the article, Calcium and Vitamin D, with a synopsis of the following clinical trial:

“A 2013 study from Germany found that with supplementing daily for 8 weeks at about 2,000 IU, D3 was more effective at raising vitamin D levels (1). The average 25(OH)D levels increased 46 nmol/l in the D3 group (for an average of 89 nmol/l) but only 30 nmol/l in the D2 group (for an average of 68 nmol/l). Vitamin D2 supplementation appeared to decrease the amount of circulating vitamin D3. PTH levels were not different between groups. Because D2 raised levels into the recommended range (50 – 125 nmol/l), it seems preliminary to assume that D3 is more healthy based on these results, though evidence is mounting that D3, even at smaller doses, can raise vitamin D levels higher or more quickly than D2.”

I don’t think this has any health implications for most vegans. If you have experienced a stubborn vitamin D deficiency, it adds some credence to the idea that you should try vitamin D3. Vegan vitamin D3 is available.


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1. Lehmann U, Hirche F, Stangl GI, Hinz K, Westphal S, Dierkes J. Bioavailability of vitamin D(2) and D(3) in healthy volunteers, a randomized placebo-controlled trial. J Clin Endocrinol Metab. 2013 Nov;98(11):4339-45. doi: 10.1210/jc.2012-4287. Epub 2013 Sep 3. | link

A Tale of Two Books

June 1st, 2015 by Jack Norris RD

In the past year or so, two comprehensive books on plant-based eating have been published by colleagues of mine–Becoming Vegan: Comprehensive Edition by Brenda Davis and Vesanto Melina and The Vegiterranean Diet by Julieanna Hever. Both books deserved a more timely review, but I figure it’s better late than never.

Becoming Vegan: Comprehensive Edition is an encyclopedia of vegan nutrition and if you are a nutrition junkie, I highly recommend it. Davis and Melina are honest and thorough in their evaluation of the literature. For those who want less, they have a shorter version of the book, Becoming Vegan: Express Edition.

As the title suggests, The Vegiterranean Diet examines the Mediterranean diet–for which there is much compelling evidence–and how it might apply to vegetarian eating. As it turns out, it applies quite well. This would be a great book to give to a family member who is suffering from type 2 diabetes, cardiovascular disease, or obesity due to poor eating habits. In addition to the nutrition information, there are over 60 recipes and many tips on weight loss which I found sensible.

Vitamin D is Absorbed Better with Fat

May 24th, 2015 by Jack Norris RD

I have updated the article, Calcium and Vitamin D, to reflect recent research showing that vitamin D supplements are better absorbed when taken with meals that contain fat.

The study was a randomized controlled trial conducted at Tufts University (1). It compared taking a 50,000 IU dose of vitamin D3 with three different meals: 1) a fat-free meal, 2) a 30% fat meal with high polyunsaturated fats, 3) a 30% fat meal with high monounsaturated fats. To make a short story even shorter, the meals with fat increased vitamin D absorption 32% over the meals without. There was no difference between meals high in polyunsaturated and monounsaturated fats.

Upcoming P-POD Conference

Registered Dietitians and Medical Doctors can earn continuing education credits at the upcoming Plant-based Prevention of Disease Conference.


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1. Dawson-Hughes B, Harris SS, Lichtenstein AH, Dolnikowski G, Palermo NJ, Rasmussen H. Dietary fat increases vitamin D-3 absorption. J Acad Nutr Diet. 2015 Feb;115(2):225-30. | link

Spring and Summer Talks by Jack Norris, RD

April 20th, 2015 by Jack Norris RD

Spring and Summer Talks by Jack Norris, RD

Thursday May 21–Elk Grove, CA
Vegan Nutrition: What Does the Science Say?
Elk Grove Vegetarian Society’s monthly meeting
Carlton Plaza | 6915 Elk Grove Blvd
Potluck at 6 pm | Talk at 6:45-7:45

Saturday June 6–Grass Valley, CA
You Are What You Eat: Education Through Nutrition
Responses to the common nutrition questions that vegans receive.
Farmed Animal Conference at Animal Place

Saturday, June 27–Madison, WI
Vegan Nutrition: What Does the Science Say?
Mad City Vegan Fest

Saturday, August 15–Santa Rosa, CA
Vegan Nutrition: What Does the Science Say?
Sonoma County VegFest

Amaranth is a Good Source of Plant-Based Protein

April 2nd, 2015 by Jack Norris RD

A reader informed me that amaranth was a good source of protein–better than quinoa even. So I checked it out and found that she was correct.

Amaranth has 9 g of protein per cup (cooked) which is slightly higher than quinoa. One cup of cooked amaranth has 250 calories while one cup of cooked quinoa has 222 calories. This gives them about the same amount of protein per calorie.

Amaranth also has a decent amount of lysine, comparable to a serving of soy or other legumes.

I have added amaranth’s amino acid profile to Table 3: Protein & Amino Acids in Common Foods.


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Links: G and Dr. G

March 30th, 2015 by Jack Norris RD

Ginny Messina has two recent posts that I thought were worth sharing:

Pinto Beans or Tofurky? How Food Choices and Motivations Affect Vegan Health

White Rice, Resistant Starch and Vegan Diets

And Dr. Michael Greger has released Latest in Clinical Nutrition – Volume 24. In Volume 24, he includes a number of videos examining the differences between organic and non-organic foods.

Incidence of Colorectal Cancer in Vegans

March 14th, 2015 by Jack Norris RD
Summary Results from Adventist Health Study-2 show vegans to have a 16% lower risk of colorectal cancer than non-vegetarians, but the finding wasn’t statistically significant. Pesco-vegetarians had the lowest rate of all.

EPIC-Oxford and Adventist Health Study-2 (AHS-2) are the two ongoing studies of diet and disease that contain a large number of vegans. This past week, AHS-2 released a report on colorectal cancer rates among various diet groups (1).

In summarizing the research on diet and colorectal cancer to date, the researchers write:

“Among dietary factors thought to influence risk, the evidence that red meat, especially processed meat, consumption is linked to increased risk and that foods containing dietary fiber are linked to decreased risk has been judged to be convincing. The evidence for a link to decreased risk has been judged as probable for garlic, milk, and calcium. Evidence for other dietary components is considered limited.”

Because of the link with red and processed meat, nutritionists had expected that vegans and vegetarians would have a lower risk for colorectal cancer. To date, EPIC-Oxford has not shown a lower risk for vegetarians (results can be seen in Cancer, Vegetarianism, and Diet).

Better news comes from the latest AHS-2 report. After an average follow-up of 7.3 years, the lacto-ovo vegetarians and vegans had a lower risk of colorectal cancer (18% and 16% respectively), but the findings were not statistically significant. Here are the risk ratios and confidence intervals for each group:

Non-Veg 1.00
Semi-Veg  .92 (.62, 1.37)
Pesco  .57 (.40, .82)
Lacto-ovo  .82 (.65, 1.02)
Vegan  .84 (.59-1.19)

The only group with a statistically significant lower risk was the pesco-vegetarians (who eat no meat other than fish), with a 43% lower risk that was highly statistically significant. Despite this, the difference between the pesco-vegetarians and vegans was not statistically significant, though close (.68, .43-1.08).

When lumping all the groups together (semi-, pesco-, lacto-ovo, and vegan) and comparing to non-vegetarians, the “vegetarians” had a statistically significant, 22% lower risk of colorectal cancer (.78, .64-.95).

Results were adjusted for age, race, gender, education, exercise, smoking, alcohol, family history, peptic ulcers, inflammatory bowel disease, diabetes mellitus, aspirin, statins, prior colonoscopy or flexible sigmoidoscopy, supplemental calcium, supplemental vitamin D, calories, and hormone therapy. Subjects were excluded if they had a prior diagnosis of cancer (except for non-melanoma skin cancer).

Overall, colorectal cancer rates in AHS-2 were lower than the population at large and AHS-2 non-vegetarian eat very little meat (54.5 g/d or just 4.5 servings per week).

Could a higher calcium intake for vegans lower their risk of colorectal cancer? In AHS-2, the vegans had slightly lower calcium intakes (801 mg/day) than the pesco-vegetarians (913 mg/day) and non-vegetarians (882 mg/day). But in EPIC-Oxford, where the results were not as positive for vegetarians, vegans had much lower calcium intakes (583 mg/day compared to 1,005 mg/day for non-vegetarians) (2).

Another difference between the EPIC-Oxford and AHS-2 groups is that the AHS-2 vegans had a substantially greater intake of both dietary fiber and vitamin C.

Does eating fish protect against colorectal cancer? The researchers write, “The existing literature provides some, although inconsistent, support for a possible protective association for fish consumption, particularly for rectal cancer; evidence for omega-3 fatty acid consumption is limited and inconsistent.” In other words, it’s not clear.

In summary, colorectal cancer rates in vegans in AHS-2 are promising, but it might be important for vegans to follow calcium recommendations not only for bone health but also to prevent colorectal cancer.


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1. Orlich MJ, Singh PN, Sabaté J, Fan J, Sveen L, Bennett H, Knutsen SF, Beeson WL, Jaceldo-Siegl K, Butler TL, Herring RP, Fraser GE. Vegetarian Dietary Patterns and the Risk of Colorectal Cancers. JAMA Intern Med. 2015 Mar 9. [Epub ahead of print] | link

2. Average calcium intakes for EPIC-Oxford calculated from Nutrient Intakes of Vegetarians and Vegans.

Vegan vs American Heart Association Diet in Obese Children

March 12th, 2015 by Jack Norris RD

This four-week study from the Cleveland Clinic was to study vegan diets in obese children.

Participants on the vegan diet were instructed to avoid all animal products and added fat, and to limit intake of nuts and avocado. They were compared to children on an American Heart Association (AHA) diet which allowed 30% of calories from total fat, 7% of calories from saturated fat, less than 300 mg of cholesterol, and less than 1500 mg of sodium daily.

After four weeks there were a number of small, but statistically significant improvements for children on the vegan diet compared to baseline: body mass index (and body weight), mid-arm circumference, systolic blood pressure, total cholesterol, CRP and MPO (measures of inflammation), and insulin.

Children on the AHA diet had improvements in body weight, mid-arm circumference, waist circumference, and MPO. The statistically significant differences in improvements between the groups were in lower body mass index and CRP for the vegan group and waist circumference for the AHA group.

Parents and children noted that it was difficult finding food on the vegan diet.

Given access to healthy plant foods, a vegan diet could provide a promising way to reduce childhood obesity.


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1. Macknin M, Kong T, Weier A, Worley S, Tang AS, Alkhouri N, Golubic M. Plant-Based, No-Added-Fat or American Heart Association Diets: Impact on Cardiovascular Risk in Obese Children with Hypercholesterolemia and Their Parents. J Pediatr. 2015 Feb 5. | link

Links on the Saturated Fat Controversy

March 1st, 2015 by Jack Norris RD

In February, the 2015 Dietary Guidelines Advisory Committee submitted the Scientific Report of the 2015 Dietary Guidelines Advisory Committee which gives recommendations to the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA) for the upcoming Dietary Guidelines. The Advisory Report is not the final Dietary Guidelines.

Of note, the Advisory Committee removed the advice to reduce dietary cholesterol and the advice to include lean meat. Ginny Messina, RD wrote a good summary of what this means for animal advocacy in her article, The 2015 Dietary Guidelines: What Will They Mean for Vegans?

On February 20, the New York Times ran an opinion piece, The Government’s Bad Diet Advice, by Nina Teicholz. It’s the typical Weston Price-type, pro-animal-product piece, in the same vein as writings by Nina Planck (no, they are not the same person).

David L. Katz, MD, MPH wrote a fun response to Teicholz’s piece, We’re Fat and Sick and The Broccoli Did It!

And speaking of Dr. Katz, he recently wrote a thoughtful piece on the Paleo diet, Paleo for a Shrinking Planet?


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TVA’s Veg Recidivism Survey

February 19th, 2015 by Jack Norris RD

In December, I blogged about the Humane Research Council’s report on vegetarian recidivism (Vegetarian Recidivism Survey, Dec 15 2014).

Another report has been released on vegetarian recidivism, this time from the Toronto Vegetarian Association. You can download the 10-page report from their post, TVA Conducts First Study of Lapsed Vegetarians in Canada.

Their study surveyed 1,112 people of which 113 were lapsed vegetarians.

Getting enough nutrients was listed at the most common challenge for lapsed vegetarians with 83% listing it as a challenge (as compared to 44% of current vegetarians). Eating out was listed as the second most common challenge, with 75% of lapsed and 65% of current vegetarians considering it a challenge.

It would be interesting to know in what way they believed getting enough nutrients was a challenge–was this theoretical or did they feel bad and suspect they weren’t obtaining enough nutrients?

The report quotes a couple of the lapsed vegetarians regarding nutrition. One person said:

“I grew tired of spending so much time on meal planning to make sure I was getting the proper amount of essential amino acids, etc.”

That makes me wonder what sort of information vegetarians are getting. While vegetarians should include high-lysine foods each day, there are so many–all legumes as well as quinoa and seitan–that it really takes little planning. Hopefully they weren’t carrying around a 1971 copy of Diet for a Small Planet, adding up all the essential amino acids from every meal.

Another respondent said:

“My iron levels were dangerously low and I needed to reintroduce meat sources of iron into my diet; I began having extreme meat cravings near the end of my vegetarianism and I believe that was my body telling me I needed the iron (which I found out later due to blood tests).”

This is disconcerting, but it also reinforces a view that I’ve been cultivating for some time–that cravings for meat might be due to iron deficiency. I would like to see research done on whether this is the case and, more importantly, how easily iron deficiency anemia can be cured while vegan by using the methods I suggest of adding vitamin C to meals and avoiding coffee and tea at meal times (more info).

I have been discussing the possibilities of this sort of research with a medical doctor at a large university and perhaps something will come of it.


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