Sunlight is the major source of

Step 1: Analyze the question The question asks which vitamin has sunlight as its major source.

Step 2: Explain the concept Vitamin D is often called the "sunshine vitamin." When ultraviolet B (UVB) rays from the sun strike the skin, a cholesterol-related compound in the skin (7-dehydrocholesterol) is converted into vitamin D3 (cholecalciferol). The liver and kidneys then convert this into the active form of the vitamin.

Why vitamin D matters:

• It helps the body absorb calcium and phosphorus from food.
• It supports strong bones and teeth.
• A deficiency causes rickets in children and osteomalacia in adults.

Step 3: Check the other options

• B. Vitamin C (ascorbic acid): Comes from fruits and vegetables such as oranges, guava, and pawpaw. A deficiency causes scurvy.
• C. Vitamin B: Comes from whole grains, beans, meat, and eggs. A deficiency causes beriberi (B1) and other disorders.
• D. Vitamin A: Comes from carrots, palm oil, liver, and green leafy vegetables. A deficiency causes night blindness.

None of these is made mainly through exposure to sunlight.

Step 4: Answer Sunlight is the major source of Vitamin D, which is option A.

Exam tip: Remember "D for Daylight" or "D for Sunshine." Also pair each vitamin with its deficiency disease, since WASSCE and JAMB often ask about these:

• A: night blindness
• B1: beriberi
• C: scurvy
• D: rickets