Vitamin Supplementation - Tolerable Upper Limits

[Russ H]

Following discussion of B12 supplementation in another thread, this document by the European Scientific Committe on Food has comprehensive information regarding tolerable upper limits for various vitamins and minerals. It is a cornucopia of useful information.

European Food Safety Authority - TOLERABLE UPPER INTAKE LEVELS FOR VITAMINS AND MINERALS

Regarding B12 particularly:

Quote

The average dietary requirement for vitamin B12, as established by the Scientific Committee for Food (Nutrient and Energy Intakes for the European Community, Reports of the SCF, 31th Series, 1993) is 1.0 μg/day, with a population reference intake (PRI) for adults of 1.4 μg/day. This is approximately the amount needed to maintain an adequate vitamin B12 body pool (about 2.5 mg), and to compensate for daily losses (about 0.1% of the total body pool).

Quote

Ileal receptors are saturated with dosages between approximately 1.5 and 2.5 μg of vitamin B12 per meal. At intakes around 1 μg about 50% is absorbed, at dosages around 25 μg only 5% is absorbed. Very small amounts (ca 1%) can be absorbed by passive diffusion, in the absence of IF.

 

Quote

There are also no adverse effects known for vitamin B12 from foods, or from supplements in amounts far in excess of needs. Some studies suggested acne formation after high parenteral doses of hydroxocobalamin, but not with cyanocobalamin, or after a combination of vitamins A, B6 and B12 given orally.

Quote

In addition, adverse effects have not been reported in the treatment of patients with compromised B12 absorption who received dosages up 1000 μg/day orally for prolonged periods; however, there was no systematic assessment of adverse effects in these patients.

 

[Scott Adams]

Thanks for sharing this!

I've been taking high levels for years, and have had high blood levels for years. I suspect that I still have issues processing it, even though my blood levels are high. The reason I suspect a possible processing issue is because whenever I lower my levels I do encounter more brain fog and memory issues, which go away when I add back the individual supplement. I also take a B-complex as well.

[Wheatwacked]

Great find @Russ314. 480 pages to read. The first thing I found is that the Referance body weight chart page 14  maxes out at 164 pounds (74.6 kg) for males over 18 and 145 pounds (66.1 kg) for females over age 60.

[Russ H]

On 6/14/2022 at 10:11 PM, Wheatwacked said:

Great find @Russ314. 480 pages to read. The first thing I found is that the Referance body weight chart page 14  maxes out at 164 pounds (74.6 kg) for males over 18 and 145 pounds (66.1 kg) for females over age 60.

Yes, that it the average body weight in Europe. I suspect in the UK it is significantly higher.

It is a useful reference document - comprehensive and conservative.

 

On 6/14/2022 at 6:29 PM, Scott Adams said:

Thanks for sharing this!

I've been taking high levels for years, and have had high blood levels for years. I suspect that I still have issues processing it, even though my blood levels are high. The reason I suspect a possible processing issue is because whenever I lower my levels I do encounter more brain fog and memory issues, which go away when I add back the individual supplement. I also take a B-complex as well.

I plan to do that. I currently take a multivitamin. Apparently the one to be careful of is B6, which can cause neuropathy when given at high doses for long periods. The safe upper limit for B6 is 25 mg per day.

[Posterboy]

Russ,

I just wanted to add this reference work on Vitamin and Mineral interactions for you to read up on it is the most comprehensive I have read on the topic.....and to introduce the concept of Co-Factors.

https://deannaminich.com/vitamin-and-mineral-interactions-the-complex-relationship-of-essential-nutrients/

Co-Factors are like the Key to your house and the deadbolt etc.

You can unlock the door with one Vitamin but the Mineral or Vitamin Co-factor will still keep the door shut.

We see this with Vitamin D and Calcium or Magnesium and Thiamine for Example....

You can take the right Vitamin sometimes and still not get the benefit you expect or are looking for....

I had to learn this the hard way......but I was lucky to find Magnesium first.....because it  helps so many things!

This article illustrates  how being low in Magnesium will "Lock you out" of the benefits of taking Thiamine for example.....

Entitled "Thiamine refractory Wernickes encephalopathy reversed with magnesium therapy"

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5093844/

And why taking a B-Complex is often better than taking one B-Vitamin alone unless the B-Vitamin you are taking is the controlling factor......your B-Vitamin won't help you (the way you intended it too)....

I see this alot in/with Folate/Homocysteine's and/or MTHFR issue etc....

People take your B-6 (and I have as a P5P in the activated B6 form) etc......and still I had no benefit etc.

I didn't know it at the time but B2 aka Riboflavin is the controlling factor for elevated Homocysteine etc.

See this article about it....

https://chrismasterjohnphd.com/blog/2019/02/26/mthfr-just-riboflavin-deficiency/

Unless you take the Vitamin/Mineral with its appropriate Co-factor(s) you won't get the improvement you seek!

Or at least it was what helped me......I have taken the B6, B9 (Folic Acid) and B12 that you always hear about.....but until I took the controlling factor of B2 aka Riboflavin my issues didn't improve.

I hope this is helpful but it is not medical advice.

Posterboy,