Vitamin D deficiency is established as <20 ng/mL in adults. So far, there is no established level for infants and children; however, most providers use the adult standard. Some providers go even further and consider all levels <30 ng/mL to define deficiency in children.
Schnapps is a type of distilled spirit that has two meanings. Essentially, schnapps are made by fermenting the fruit along with the base liquor (usually brandy), whereas liqueurs are often made by steeping fruits in alcohol after fermentation and/or distillation.
Pimms is a fruit cup (a type of English specialty drink) that is often considered to be a liqueur. There are several types and all are usually mixed with gin, although vodka is used for some. It's rarely consumed alone and is mixed with hard alcohol and often garnished with fruit, hence the name.