Disposable income → Vitamin / mineral supplementation
Money buys bottles. Reverse causation is the whole trick of the wellness-to-wealth genre.
Observational · High confidence
Supported by an experiment or a tightly identified design. Still read the caveats.
Mechanism
Supplements are inexpensive relative to rent and expensive relative to nothing. Demand rises with income and with health insurance culture. Once this arrow exists, the reverse observational arrow is unidentified.
Caveats
Not an RCT of cash transfers on pill purchases, but the demand curve is not in serious dispute.
Effect
qualitative. Pills are normal goods. This is the arrow people reverse.
Nodes
Named confounders
Cite this page
What Causes What. “Disposable income → Vitamin / mineral supplementation.” https://whatcauseswhat.org/edges/e-income-buys-supplements (atlas updated 2026-08-31).
Papers
- Healthy user and related biases in observational studies of preventive interventions: a primer for physicians
W. H. Shrank, A. R. Patrick, M. A. Brookhart · 2011 · Journal of General Internal Medicine