Rickets results from vitamin D deficiency

Steps:

• Recall rickets is a bone disorder in children due to inadequate vitamin D, calcium, or phosphate.
• Identify vitamin D sources: dietary (dairy, eggs) and sunlight (skin synthesis).
• Evaluate options for deficiencies in these sources.
• Match D to combined lack of diet and sunlight exposure.

Why D is correct:

• Vitamin D deficiency causes rickets by impairing calcium absorption, as defined in nutritional pathology; low dairy/eggs reduce intake, while minimal sunlight prevents endogenous production.

Why the others are wrong:

• A: Targets niacin deficiency, linked to pellagra from low whole grains.
• B: Indicates thiamine deficiency, causing beriberi from polished rice diets.
• C: Suggests vitamin C deficiency, leading to scurvy from poor fresh produce.

Final answer: D