Vitamin D Mistake – who got it so wrong!

In this video, Dr John Campbell describes what he says is a major statistical error. He says the Institute of Medicine (now the National Academy of Medicine) made the error. He also says the error later shaped Vitamin D guidelines in the United Kingdom.

He focuses on the Recommended Dietary Allowance (RDA) for Vitamin D. He argues the official recommendations (600 IU in the US and 400 IU in the UK) sit far too low.

The core mistake he alleges

According to Dr Campbell, the issue comes from how the data was handled. Specifically, he claims the calculation used average study data rather than individual participant data. As a result, he argues the estimated requirement looks much lower than it should.

He puts the corrected requirement at about 8,895 IU per day for most people. In other words, he says this figure is over 15 times higher than the official recommendation.

Why he says it matters

Dr Campbell argues that authorities have not corrected this “schoolboy error” for more than a decade. Because of that, he believes there are serious public health consequences.

In practice, he links the issue to blood Vitamin D levels. For that reason, he argues the current recommendations do not get most people to adequate levels. More importantly, he also argues the recommendations fall short even for basic bone-health goals.

Consequences for disease and injury prevention

Dr Campbell says the current recommendation of 600 IU per day will not meet bone-health objectives. Beyond that, he argues it will not support disease and injury prevention outcomes.

Bone health and deficiency

In his view, the Institute of Medicine set the RDA to prevent rickets and bone disease. He connects that target to a blood level of 50 nmol/L. However, he argues the recommended intakes do not reliably reach that level.

Cancer, diabetes, dementia, immunity, and heart disease

Dr Campbell argues that people need more Vitamin D than the current dose to support broader health outcomes. To explain this, he highlights several areas:

• Cancer: Higher Vitamin D levels are linked with fewer prostate cancer deaths, he says. Additionally, he notes an association with colon cancer.

• Diabetes: Vitamin D may protect against pre-diabetes progressing to diabetes, according to Dr Campbell. For example, he cites a 76% reduction between high and low Vitamin D levels. He also mentions a link to type 1 diabetes.

• Dementia: Observational studies suggest higher Vitamin D relates to less dementia, he says.

• Immunity and heart disease: Vitamin D supports immunity and, similarly, links to heart disease outcomes, in his view.

His overall conclusion

Overall, Dr Campbell frames Vitamin D adequacy as a basic, low-cost public health intervention. At the same time, he argues the ongoing RDA error leaves people below needed levels. Consequently, he says this allows preventable illness to continue.

To illustrate the point, he compares it to a classroom system. He says a “passing average” still leaves many individuals failing. Likewise, he argues the same pattern applies to Vitamin D intake guidance.