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What Causes What
SMOKE0 NULL

Vitamin / mineral supplementation → Employment status

A rise in Vitamin / mineral supplementation does not identify a change in Employment status.

People who buy vitamins look more employed because they already differ in ways that keep jobs, not because the pill caused the job. Shrank (2011) named that healthy-user bias. Simpson (2006) measured the same selection as death, not employment: in 21 studies and 46,847 people, good adherence, including to placebo, had an odds ratio of 0.56 for mortality.

Observational · High confidence

The association disappears when you account for other factors, like socioeconomic status or healthy-user bias.

Mechanism

Shrank, Patrick, and Brookhart (2011) named the healthy-user and healthy-adherer biases. People who take one preventive therapy also take others. They exercise more, show up for screening, and fill other bottles. An observational study that treats the pill as the cause will credit the pill for those other traits. That is the healthy-user effect. The related bias is healthy adherer: people who keep taking a preventive pill look healthier than people who stop. Shrank's striking example is placebo. Patients who take their sugar pills die less than patients who do not. Shrank also notes that observational vitamin stories, including beta carotene and vitamin E, later failed in trials. Simpson, Eurich, Majumdar, and colleagues (2006) are that placebo example. They pooled 21 studies and 46,847 people. Eight studies had placebo arms (19,633 people). Good adherence versus poor adherence had an odds ratio of 0.56 for death (95% CI 0.50 to 0.63). Good adherence to placebo had the same odds ratio, 0.56 (0.43 to 0.74). Good adherence to a useful drug was 0.55 (0.49 to 0.62). Good adherence to a harmful drug raised death (odds ratio 2.90). The pill can still work. The selection is who takes it. Simpson measured mortality after heart attacks, in HIV care, in primary prevention, and in diabetes. He did not measure jobs. The folk story on this pair is that vitamins make careers. That is the same selection, pointed at employment. Multivitamin buyers are selected on cash, education, and the habit of taking the bottle. Those traits keep people employed. Simpson is here as the mechanism of the smoke: adherers look healthier even when the pill is a placebo. He is not here as an employment finding.

Caveats

Simpson's outcome is death, not a job title and not a vitamin. The 21 studies cover post-infarct drugs, HIV regimens, primary-prevention aspirin and pravastatin, diabetes, statins, digoxin, and transplant immunosuppression. He is on this pair as the mechanism of the smoke: the same selection that makes adherers look healthy on placebo will make vitamin buyers look employed. He did not measure employment. The meta-analysis is observational. Simpson could not adjust for diet, exercise, clinic follow-up, or depression with individual data. Placebo-arm results had more scatter than the useful-drug results. Most adherence measures were indirect. Pill counts and refills assume the bottle that left the pharmacy was swallowed. Shrank is a primer, not a labor-market regression. Correcting a documented B12, iron, or D deficiency can restore function in deficient people. That is a medical effect on fatigue or cognition, not a career effect. This page does not speak to fish oil and jobs, to cash buying bottles, or to genetic vitamin D and employment. Those are other edges.

Effect

qualitative. Healthy-adherer smoke. Simpson: placebo adherers die less (OR 0.56, 21 studies). Shrank names the same selection for preventive pills. Simpson measured death, not jobs.

Nodes

Lifestyle & environmentVitamin / mineral supplementationSocioeconomic statusEmployment status

Named confounders

Cite this page

What Causes What. “Vitamin / mineral supplementation → Employment status.” https://whatcauseswhat.org/edges/e-supplements-employment (atlas updated 2026-09-02).

https://whatcauseswhat.org/edges/e-supplements-employment

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