Question

question 13 preliminary clinical research indicates that a deficiency of vitamin k may ______. weaken bones; cause reproductive problems; cause hair loss; have no physical effects

Explanation:

Vitamin K is involved in bone metabolism (e.g., helps in bone mineralization and regulating osteocalcin). Deficiency can lead to reduced bone strength. Reproductive problems are more linked to vitamins like D, E or hormonal issues, hair loss to vitamins like B, D or iron, and vitamin K deficiency does have physical effects (e.g., bleeding issues, bone problems), so "weaken bones" is correct.

Answer:

A. weaken bones