Sunday, August 4, 2024

About Vitamin B12

Cobalamin is the only water-soluble vitamin stored in the body. About 3 mg of cobalamin are stored, of which 1 mg is stored in the liver. Hence, it takes 3-5 years to develop a vitamin B12 deficiency after a total gastrectomy. In contrast, significant amounts of folate are not stored. Clinical evidence of folate deficiency can occur within a month after folate intake is stopped.

https://www.medscape.com/answers/204066-119195/what-is-the-role-of-cobalamin-and-folate-storage-in-the-pathogenesis-of-megaloblastic-anemia


https://www.b12-vitamin.com/body-store/


However, this impression is put into perspective if you consider the actual intake: from the 1000 µg, only a maximum of 12 µg is actually absorbed by the body with a single oral dose; only 480% of the daily requirement (2). 

https://www.b12-vitamin.com/high-dose/



One review recommended that those with vitamin B12 deficiency take 1 mg of vitamin B12 daily for a month, followed by a maintenance dose of 125–250 mcg per day (18Trusted Source).

https://www.healthline.com/nutrition/vitamin-b12-dosage#suggested-dosages

Typically, about 56 percent of a 1-microgram dose of B-12 is absorbed, and that rate of absorption decreases drastically if you take more than 2 micrograms at a time, the Office of Dietary Supplements explains. For example, if you take a 500-microgram pill, your body absorbs only about 10 micrograms.


But a normal level of vitamin B12 in your bloodstream is generally between 190 and 950 picograms per milliliter (pg/mL). Between 200 to 300 pg/mL is considered borderline and your doctor may do more testing. Below 200 pg/mL is low and more testing is needed.

https://www.webmd.com/a-to-z-guides/vitamin-b12-test

HealthVit Vitamin B12 500mcg Tablet
West-Coast Pharmaceutical Works Ltd
https://www.1mg.com/otc/healthvit-vitamin-b12-500mcg-tablet-otc340915



January 30, 2024
Analysis Says Excessive Vitamin B12 Concentration Can Increase Mortality Risk
Author(s):

Hayden E. Klein
Elevated serum vitamin B12 concentration was positively associated with all-cause mortality risk, particularly among older adults, with concentrations exceeding 400 pmol/L showing significantly higher mortality rates.
https://www.ajmc.com/view/analysis-says-excessive-vitamin-b12-concentration-can-increase-mortality-risk







Recommended guidelines for  supplements

For normally healthy children and adults,  high-dose B12 supplements are a waste of money. 

Instead, take the recommended daily allowance (RDA) without dramatically overdoing it. In adults, the body needs only 2.4 mcg daily. Pregnant women need 2.6 mcg daily. Breastfeeding women need 2.8 mcg per day. 

Large doses and injections are only needed in people who have been diagnosed with vitamin B12 deficiency. 

The National Institutes of Health Office of Dietary Supplements has a useful list of B12 food sources, including animal products, nutritional yeast, seafood, dairy products, breads, and breakfast cereals.


Excess Vit B12 - Side Effects

Article
JOURNAL ARTICLE
The pathophysiology of elevated vitamin B12 in clinical practice 
E. Andrès, K. Serraj, J. Zhu, A.J.M. Vermorken
QJM: An International Journal of Medicine, Volume 106, Issue 6, June 2013, Pages 505–515, https://doi.org/10.1093/qjmed/hct051
Published: 27 February 2013

(To  be read again)


https://redcliffelabs.com/myhealth/food-and-nutrition/some-side-effects-of-vitamin-b12-if-taken-excessively/

How to Get Rid of Excess Vitamin B12
By Naomi Parks
https://www.livestrong.com/article/407648-how-to-get-rid-of-excess-vitamin-b12/

Open access
Published: 25 June 2021
Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer


Ud. 5.8.2024
Pub. 25.4.2022























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