This video was released on YouTube on December 7, 2025
(As of this posting on January 10, 2026, 874,000 views on YouTube.)
Link to NIH (National Library of Health, US) article: A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D (2014)
- U.S.: nearly 15 times too low
- U.K.: over 22 times too low
IOM Calculation
600 units (15 mcg):
97.5% of people will achieve 63 nmol/L
(25.2 ng/mL)
Correct Calculation
600 units (15 mcg):
97.5% of people will achieve 26.8 nmol/L
(10.7 ng/mL)
**Requirements Based on Correct Calculation**
8,895 IU of vitamin D per day may be needed to ensure that 97.5% of individuals achieve serum 25(OH)D levels of 50 nmol/L or more.
This highlights “The Average vs. Individual” mistake.
Canada Studies
- Diet provides 232 IU of vitamin D per day
- Institute of Medicine (IOM) RDA: 600 IU per day (ages 1–70)
The Institute of Medicine is now called the National Academy of Medicine
https://nam.edu
United Kingdom
The U.K. recommendations are even lower:
- 400 IU (10 mcg) per day
- 600 IU per day was believed to achieve serum 25-hydroxyvitamin D (25(OH)D) levels of 50 nmol/L or more in 97.5% of healthy individuals
Levels of 50 nmol/L or more have been shown to benefit bone health and help prevent disease and injury.
How the IOM Reached Its Conclusion
- The IOM based its vitamin D RDA on 10 supplementation studies (32 dose protocols)
- These studies were conducted during winter months, at locations above the 50th parallel
- The IOM regressed the 32 study averages (dose-to-plasma ratio)
- Based on this, the IOM estimated that 600 IU would achieve an average 25(OH)D level of 63 nmol/L
Requirements Based on Correct Calculation
8,895 IU of vitamin D per day
This dose is well above the current RDA of 600 IU per day and the tolerable upper intake level of 4,000 IU per day.
Public Health Implications
The public health and clinical implications of this miscalculated RDA are serious.
With the current recommendation of 600 IU per day, bone health objectives and disease- and injury-prevention targets will not be met.
The authors recommend that the RDA for vitamin D be reconsidered to allow for appropriate public health and clinical decision-making.
The Big Vitamin D Mistake
Link to NIH (National Library of Health, US) article: The Big Vitamin D Mistake
Explanation of the Statistical Error
“The Average vs. Individual” Mistake
The Institute of Medicine’s goal was to find a vitamin D dose that ensures 97.5% of individuals reach a healthy blood level (50 nmol/L).
The statistical error occurred because the IOM analyzed study averages rather than individual participant data.
- They examined 10 studies
- They used the average blood level achieved in each study
- They calculated a statistical range (confidence interval) based on those averages
- They concluded that 600 IU would allow 97.5% of study averages to reach the target
The Problem
There is far less variation between averages than there is between individuals.
By using averages, the IOM unintentionally smoothed out individual differences.
They assumed that if the average person in a study met the target, then nearly everyone did.
The Classroom Analogy
Goal: Ensure every student passes a test.
The IOM method:
They looked at the average scores of 30 classrooms and set standards so that 97.5% of classrooms had a passing average.
The reality:
Even in classrooms with passing averages, some students still fail.
The Correction
To ensure 97.5% of students pass, you must look at the lowest-performing individuals, not the classroom average.
The Consequence
When the authors recalculated the data using individual variation rather than study averages, they found:
- 600 IU per day does not ensure 97.5% of people reach 50 nmol/L
- Instead, it ensures 97.5% reach only 26.8 nmol/L, far below the target
To actually ensure that 97.5% of the population reaches 50 nmol/L, the calculations indicate a required dose of approximately 8,895 IU per day.