What's the recommended daily intake of B12 in your country?
While early studies suggested that we only need less than half a mcg/day B12, I don't think they took some important factors into consideration back then. We don't absorb all the B12 we consume, and we're exposed to a lot of B12 'enemies' regularly. Plus - the more B12 you take, the lower percent of the B12 you consume will be absorbed (which is bad news for meat eaters and people who think they'll absorb 10 mcg B12 if they take a 5% mcg B12 pill.
The recommended B12 values have been adjusted a few times - both up and down. I recently read that meat eaters consume around 5 mcg daily, but another article suggested that they consumed 5-15 mcg daily.
From Wikipedia:
Quote:
Current recommendations
The current Dietary Reference Intake recommendation is composed of:
Estimated Average Requirements (EAR), expected to satisfy the needs of 50% of the people in that age group based on a review of the scientific literature.
Recommended Dietary Allowances (RDA), the daily dietary intake level of a nutrient considered sufficient by the Food and Nutrition Board to meet the requirements of nearly all (97–98%) healthy individuals in each life-stage and gender group. It is calculated based on the EAR and is usually approximately 20% higher than the EAR (See "Calculating the RDA", below).
Adequate Intake (AI), where no RDA has been established, but the amount established is somewhat less firmly believed to be adequate for everyone in the demographic group.
Tolerable upper intake levels (UL), to caution against excessive intake of nutrients (like vitamin A) that can be harmful in large amounts. This is the highest level of consumption that current data have shown to be safe.
The RDA is used to determine the Recommended Daily Value (RDV) which is printed on food labels in the U.S. and Canada.
For B12, the Estimated Average Requirements (EAR) is 2.0 mcg and the RDA/AI is 2.4 mcg - both based on USDA/National Nutrient Database for Standard Reference, SR23, (2010).
Here's an article from 2006, suggesting that the RDA "in Europe" should be increased from 1 mcg to 6 mcg:
Quote:
The current study calculated dietary and supplemental intake of vitamin B12 for 98 post-menopausal women with an average age of 57 using three-day diet records, a method that does not rely heavily on memory and widely believed to give the most valid estimated of intake.
After dividing the volunteers into quintiles depending on B12 intake, the researchers measured four different vitamin B12-related serum markers.
Despite the range of intake varying from three to 15 micrograms, the researchers observed that the curves leveled off at a daily intake of about six micrograms for all the variables analysed.
"A daily vitamin B12 intake of six micrograms appears to be sufficient to normalize all of the vitamin B12-related variables, which suggests that this dose might be more adequate for the general adult population than the current RDA," concluded Bor.
The results may have implications for vitamin producers and supplement makers. Average commercial multivitamin supplements in Denmark contain only 1 microgram of vitamin B12, while in the Netherlands the average is 2 micrograms. Some multivitamin formulations in the UK contain as little as 0.5 micrograms.
Vitamin B12 deficiency is believed to be rare, except amongst vegetarians. A balanced western diet normally contains five to seven micrograms of the vitamin. Vegetarian and vegan diets however require vitamin B12 supplements to maintain healthy levels. According to a 2002 Datamonitor study there are approximately 13 million vegetarians in Europe.
It's unclear to me whether the official B12 recommendations already takes into consideration both that we don't absorb all the B12 we eat, and that there are lots of B12 "enemies" out there will influence B12 levels. But the general recommendation in most countries are than the 0.1 mcg B12 Dr. Herbert suggested that would be sufficient for most people. Health Canada suggests these daily values (which are kind of strange).
According to this book, "The median intake of vitamin B12 from food in the United States was estimated to be approximately 5 µg/day for men and 3.5 µg/day for women" and "In one Canadian province the mean dietary intake was estimated to be approximately 7 µg/day for men and 4 µg/day for women."
From another thread:
Quote:
Dr. Herbert wrote that 'the minimum daily requirement (MDR) for vitamin B12 to sustain normality is probably in the range of of ~0.1 mcg. 0.2-0.25 mcg absorbed daily from food is probably adequate for anybody. There are no objective published data that larger amount of vitamin B-12 have any added value for greater health or longer life' and that 'We (the 1980-85 RDA Committee) reduced the RDA for vitamin B12 to 2mcg for adults (which is still more than more than anybody needs) because there was no scientific basis for higher amounts. As delineated above, nobody needs that much, there is no evidence that it has any value whatsoever for humans and, as we discover more and more about the excess of any nutrient, we discover harms we did not know existed. It will probably turn out eventually that too much vitamin B12, like too much of everything, is harmful"
But in spite of assuming that mount of B12 to sustain normality is probably in the range of of ~0.1 mcg and that 0.2-0.25 mcg absorbed daily from food is probably adequate for anybody, the current recommendations are circa 10 times as high in many countries. AFAIK, most B12 manufacturers also recommends that the one tablet (2-3 mcg) is enough per day, and that children need less than that.
Here's a list I just found showing the RNI/RNA for US, Canada and UK, showing that for men and non-pregnant/non-lactating women, the values were 2 mcg (USA and Canada) and 1.5 mcg (UK) in 2006. This site seems to have newer info. I'll update this post later - so please post info about current recommendations in your country in this thread!
Re: What's the recommended daily intake of B12 in your country?
This is quite interesting! After looking it up, I found that the recommended intake of B12 in Norway is:
2 mcg for both men and women.
2 mcg for pregnant women
and 2.4 mcg for women who are breast-feeding.
The highest legal amount of B12 in supplements is 9 mcg
Re: What's the recommended daily intake of B12 in your country?
I've been looking into B12 recommendations and the NHS UK site still lists the UK RDA as 0.0015mg (or 1.5 mcg). I thought I might be getting too little (for some reason I assumed the RDA levels on the side of Soya milk cartons were accurate - Alpro says 2.5mcg and the Vegan Society says 3mcg) but didn't want to start supplementing with a multi until I finished my current stock of Iodine pills.
Looking at what I eat in a day, I probably get more than that from Soya Lattes alone. I currently aim for 3mcg a day from foods/drinks (sometimes get less/sometimes get more 4-5mcg).
