Supplements for 1 year

Has anyone given the following supplements for their 1 year old? Sambucol drops (for immunity) Biogaia probiotics (for gut health) DHA drops by Nordic Naturals (for brain development) I’m thinking to start the following supplements when my baby turns 1 year old. The first 2 is in preparation for building immunity for school when baby goes in at 18 months. DHA I heard some good things. Is it ok to start all 3 supplements? Please share your thoughts or other recommendations.