Vitamin C: Correct Statements

The question asks which of the four given statements about vitamin C (ascorbic acid) are correct. The correct answer is option 2 ("3 and 4").

Analysis of Each Statement

• Statement 1: It is heat stable — Incorrect. Vitamin C is one of the least stable vitamins. It is easily destroyed by heat, boiling, prolonged cooking, exposure to air (oxidation), light, and alkaline conditions. This is precisely why cooking and pasteurization/boiling of foods and milk markedly reduce their vitamin C content.
• Statement 2: Normal platelets are poor in ascorbate — Incorrect. In reality, platelets and leukocytes concentrate ascorbic acid to levels many times higher than plasma; buffy coat (WBC) ascorbate levels are in fact used as a more reliable index of body vitamin C stores than plasma levels. Normal platelets are therefore rich in ascorbate, not poor.
• Statement 3: Perifollicular hyperkeratosis is a clinical sign of scurvy — Correct. Vitamin C is essential for collagen synthesis (hydroxylation of proline and lysine). Its deficiency (scurvy) classically presents with follicular hyperkeratosis, perifollicular hemorrhages, corkscrew hairs, swollen/bleeding gums, and poor wound healing. Perifollicular hyperkeratosis with hemorrhage is a well-recognized early cutaneous sign of scurvy.
• Statement 4: Infants fed exclusively on boiled milk are vitamin C deficient — Correct. Since vitamin C is heat-labile (as established in Statement 1), boiling milk destroys most of its already-low vitamin C content. Infants who are fed only boiled milk (without any vitamin C supplementation from fruits, formula, or juices) are therefore at risk of developing infantile scurvy — a classically described cause of vitamin C deficiency in infants.

Conclusion

Statements 3 and 4 are the medically accurate statements — perifollicular hyperkeratosis is indeed a sign of scurvy, and infants exclusively fed boiled milk can become vitamin C deficient because boiling destroys the vitamin. Statements 1 and 2 are both factually wrong, since vitamin C is heat-labile (not heat-stable) and platelets are normally rich in (not poor in) ascorbate. Hence, the correct answer is "3 and 4".