SNP rs17713054 SLC6A20-LZTFL1 was associated with increased risk of severe COVID-19 in the entire group (risk allele A, OR = 1.78, 95% CI = 1.22–2.6, p = 0.003), obese individuals (OR = 2.31, 95% CI = 1.52–3.5, p = 0.0002, (pbonf = 0.0004)), patients with low fruit and vegetable intake (OR = 1.72, 95% CI = 1.15–2.58, p = 0.01, (pbonf = 0.02)), low physical activity (OR = 1.93, 95% CI = 1.26–2.94, p = 0.0035, (pbonf = 0.007)), and nonsmokers (OR = 1.65, 95% CI = 1.11–2.46, p = 0.02). Here, SLC6A20 is linked to COVID-19.