Table 1.

Differences in age at recruitment to the UK Biobank for published genetic predictors of testosterone²⁸, smoking²⁹, and vitamin C (absorbate)³⁰ using Mendelian Randomization inverse variance weighted estimates.

Exposure type	Exposure	Difference in age at recruitment (years)	95% CI	p value
Positive control	Smoking initiation compared to not	− 0.37	− 0.50 to − 0.25	5.2e−9
Negative control	Absorbate (rs33972313)	− 0.01	− 0.11 to 0.09	0.79
Exposure	Testosterone (standard deviation)	− 0.10	− 0.20 to − 0.004	0.04