Breast milk or iron-fortified infant formula has everything your baby needs until around 6 months of age. Newborn babies have small tummies and need to eat every 2 to 3 hours or about 8 to 12 times per day.
Tack vs. tact. Tact is sensitivity in social situations. A tack is a course or an approach (the word has nautical origins). When switching courses or taking a different approach, one changes tack, not tact. Tact often appears in place of tack. Presumably some people think of it as short for tactic, which is synonymous with tack in some contexts.
C17: from Latin tactus a touching, from tangere to touch. Word Origin and History for tact Expand. n. 1650s, sense of touch or feeling (with an isolated instance from c.1200), from Latin tactus touch, feeling, handling, sense of touch, from root of tangere to touch (see tangent). Meaning sense of discernment, diplomacy, etc. first recorded 1804, from a sense that developed in French cognate tact.