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How were vitamins and daily requirements determined by usda?

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Dr. Derrick Lonsdale
Preventive Medicine

In brief: By a team

Of "experts". Each was asked how much of this and that vitamin is essential and the average of their answers was used to compile the rda, e.
g. Thiamine (vitamin b1) rda is 1 to 1.5 mg/day. But prolonged deficiency damages essential enzymes and the traditional deficiency disease is beriberi. It required 100 mg of thiamine 3 times a day for months to treat. Thiamine def is common today.

In brief: By a team

Of "experts". Each was asked how much of this and that vitamin is essential and the average of their answers was used to compile the rda, e.
g. Thiamine (vitamin b1) rda is 1 to 1.5 mg/day. But prolonged deficiency damages essential enzymes and the traditional deficiency disease is beriberi. It required 100 mg of thiamine 3 times a day for months to treat. Thiamine def is common today.
Dr. Derrick Lonsdale
Dr. Derrick Lonsdale
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