奶蛋素

• 女(woman; female)RADICAL
• 乃(then; also (suggests 'nãi'))PHONO-SEMANTIC

Grandmother and mother's milk attach to the woman radical, sounding like "nãi" similar to the character 乃.

• 疋(foot; leg (sound similar to 'đản'))PHONETIC
• 虫(insect; reptile)RADICAL

An egg is what reptiles lay, with a round shape like a foot.

• 糸(silk thread; filament)RADICAL
• 龶(coarse undyed thread bundle; top part of thread)ASSOCIATIVE

Raw silk that hasn't been dyed suggests the meaning of pure, simple, and basic.