Vitamin supplemetation: mega dozes and timed release

Question
Hello,

I have been taking "Good N Natural Ultra Man High Potency [Timed Release]" supplements for the past days, which was recommend by a worker in a Natural food store. I have two questions.

1) Are "High Potency" Multivitamin safe? According to Supplement facts of my multivitamins, I am getting 5,000% of B-12, 2,000% of Thiamin, 1,755% of Ribofalvin, 1,500% of B-6. The other vitamins doesn't have that high of doses, but I thinking that these doses are too high. Is this true?

2) Are "Timed Released" Supplements better?

Thanks.

Answer
Dear Ignatius,


The problem of vitamin supplementation dozes is very controversial. The official (NIH) standpoint is, "Although the megavitamin therapy have been used for the prevention and treatment of diseases and illnesses such as cancer, heart disease, schizophrenia, and the common cold, some high dose or megavitamin regimens can produce adverse or toxic effects."

Let's take the vitamin B6 as an example.

Megavitamin treatment involves using doses of vitamins that are more than 10 times the recommended daily allowance. For example, the US "no-observed-adverse-effect" level for B6 is set at 200 mg, safe upper limit at 100 mg and recommended daily amount (RDA) 2 mg.

Meanwhile, pyridoxine-HCl used in treating some metabolic disorders has been given in doses reported as high as 1,500 mg/day. Studies of megadozes of vitamin B6 on men and rats showed no changes in appetite but an increased muscle mass, decreased total body fat as well as fat cell size.

At dozes as high as 400 mg vitamin B6 daily no side effects were reported in the study published in the American Journal of Clinical  Nutrition.

As to the timed-release form versus single-doze form, it depends on what's called pharmacokinetics of a drug or vitamin. In some cases like prednisone for the morning joint stiffness but it sounds very logical: instead of waking up, taking the pill and waiting when it starts working, the timed-release pill begins releasing the drug before while you are still sleeping. I fail seeing such logic in case of vitamins.

Reading

Megavitamins may be useful treatment for many genetic diseases, or just good insurance to tune up body's metabolism
http://atkinszone.com/did-you-know/2006/10/megavitamins-may-be-useful-treatment....

Opinion: 95% supplements is a waste of money
http://atkinszone.com/exercise/2008/08/opinion-95-supplements-is-waste-of.html

Coburn, W. Schaltenbrand, J.D. Mahuren, R.J. Clausman and D. Townsend, Effect of megavitamin treatment on mental performance and plasma vitamin B6 concentrations in mentally retarded young adults. Am J Clin Nutr 38 (1983), pp. 352?55.

Efficacy of modified-release versus standard prednisone to reduce duration of morning stiffness of ?
F Buttgereit, G Doering, A Schaeffler, S Witte, S ?- The Lancet, 2008  

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