What is a common cause of vitamin K deficiency in adults?

What is a common cause of vitamin K deficiency in adults?

• A. Chronic antibiotic use leading to loss of colonic flora
• B. Pancreatic insufficiency causing fat malabsorption
• C. Excessive intake of leafy greens
• D. Vitamin K supplementation

Answer: (A)

Vitamin K deficiency in adults most often comes from disruption of the gut bacteria that produce vitamin K. The colon harbors bacteria that synthesize menaquinones, which contribute to daily vitamin K requirements. Broad-spectrum antibiotics can wipe out these colonic flora, reducing endogenous vitamin K production and leading to deficiency. This deficiency impairs gamma-carboxylation of clotting factors II, VII, IX, and X (and proteins C and S), causing a bleeding tendency and often a measurable drop in the prothrombin time. While fat malabsorption from pancreatic insufficiency can also cause deficiency, it’s less common than antibiotic-associated disruption. Eating leafy greens supplies vitamin K, and supplementation would prevent deficiency.

Vitamin K deficiency in adults most often comes from disruption of the gut bacteria that produce vitamin K. The colon harbors bacteria that synthesize menaquinones, which contribute to daily vitamin K requirements. Broad-spectrum antibiotics can wipe out these colonic flora, reducing endogenous vitamin K production and leading to deficiency. This deficiency impairs gamma-carboxylation of clotting factors II, VII, IX, and X (and proteins C and S), causing a bleeding tendency and often a measurable drop in the prothrombin time. While fat malabsorption from pancreatic insufficiency can also cause deficiency, it’s less common than antibiotic-associated disruption. Eating leafy greens supplies vitamin K, and supplementation would prevent deficiency.