A doctor examined a child and revealed symptoms of rachitis. Development of this desease was caused by deficiency of the following compound:

Answer options

1. Retinol
2. Biotin
3. 1,25 [OH]-dichydroxycholecalciferol
4. Naphtaquinone
5. Tocopherol

Explanation

Rachitis refers to rickets. Deficiency in vitamin D in conjunction with inadequate sun exposure causes osteomalacia (or rickets when it occurs in children), which is a softening of the bones. Thus, deficiency results in impaired bone mineralization and bone damage. Calcitriol (vitamin D3) usually refers specifically to 1,25 (OH) -dihydroxycholecalciferol.