SECTION HEADS ARE ALSO LINKS TO PAGES
12 Questions Answered Regarding
Vitamin B12, Excerpts
By Thomas Campbell, MD February 6, 2015
"How is B12 made?
B12 is made by anaerobic microorganisms (ie. bacteria that do not require oxygen to live) ... common in the gastrointestinal tract of animals [including humans].
"What foods might naturally contain B12?
Animal foods and two varieties of edible algae (Dried green (Enteromorpha sp.) and purple (Porphyra sp.) seaweed (nori)) have been found to have active B12.
Plants grown in experimental settings with B12-enriched soils or water (with hydroponic processes) actually take up B12. Some varieties of mushrooms and some foods made with certain fermentation processes have very small amounts of active B12.
"How do animals get B12?
They absorb B12 made by their gut bacteria, in the case of ruminants like cows and sheep. They eat poop (coprophagia),
like some rodents do. (Please don’t get any bright ideas from
this fact!) They have bacterial contamination of their food. They eat animal-sourced foods like other animal flesh, milk, or eggs.
[Commercial animals in the U.S. are given B-12 supplementation, as most are in factory farms, do not graze, are fed grain-based diets based upon soy and corn, and are fed 'other things'.
"Who is at risk for B12 deficiency?
Adults over the age of 50 may not absorb B12 as well. A B12 supplement or fortified foods are recommended for all adults
over age 50, regardless of diet. Some conditions and diseases
can predispose someone to B12 absorption problems [consult
with your healthcare provider]. Metformin, the common
diabetes drug, may also lower B12 absorption.
"I don’t eat animal foods. How much B12 should I take?
For the general adult population, a daily dose of the smallest available tablet of B12 (usually 100 mcg) should be sufficient. Consult with your healthcare provider.
"What form B12 should I take?
You can take cyanocobalamin or methylcobalamin. Both have been shown to increase B12 levels. If you are concerned with deficiency or maximizing absorption, chewable or dissolvable tablets are much better absorbed."
Previously assumed to be only- or
mostly-available in animal products.
An important trace mineral
Serving Size Micrograms
Seaweed (whole / 1 sheet) 1 gram* 16–3,000
(Consume in very small amounts to avoid overdose)
Himalayan Crystal Salt 1 gram* 250
Dried Prunes 5 prunes 13
Navy Beans 1/2 cup 32
Lima Beans 1/2 cup 8
Bananas 1 medium 3
Strawberries 1 cup 13
Canned Corn 1/2 cup 14
Cranberries 4 ounces 400
Green Beans 1/2 cup 3
Baked Potato with Peel 1 medium 60
* 1 tsp = 5 grams
• Bembu.com: http://bembu.com/iodine-rich-foods
• National Insitutues of health, Office of Dietary Supplements.
Recommended Dietary Allowances (RDAs), micrograms (mcg)
Age Male Female Pregnancy Lactation
Birth — 6 mo. 110* 110*
7–12 months 130* 130*
1–3 years 90 90
4–8 years 90 90
9–13 years 120 120
14–18 years 150 150 220 290
19+ years 150 150 220 290
* Adequate Intake (AI)
Reference: National Institute of Health (NIH), Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/ Iodine-HealthProfessional/#h2
"To reach the circulating (25-hydroxy) vitamin D levels associated with the lowest overall mortality, one may need to take supplements, given data suggesting suboptimal production from sun even under optimal circumstances. 2000 international units a day may be just right."
— Dr. Greger, NutritionFacts.org
Vitamin D is needed for maximum calcium absorbency.
View: Calcium and Vitamin D: Important at Every Age
for age-related recommendations.
Heart-Centered Humans for Animals' Rights and Protection
Do Carnivores need vitamin B-12 supplements?
By Dr. Jennifer Rooke, October 30, 2013. http://baltimorepostexaminer.com/carnivores-need-vitamin-b12-supplements/2013/10/30
Vitamin D: The Sunshine-Based Vitamin
2000 IU a day may be needed
Iron in plant foods is non-heme and needs Vitamin C for maximum absorbency. Vitamin C amounts per cup, in the above foods, include: Spinach: 8.4 mg, Swiss Chard: 10.8 mg, Lentils: 3.2 mg,
Kidney Beans; 8.3 mg, Cashews: .8 mg, Tofu: 0.2.
Recommended Dietary Allowances for Iron
— National Institute of Health