Which of the following would NOT lead to increased pigmentation?

A. growth hormone
Deficiency in GH during childhood leads to dwarfism or delayed growth, so it’s definitely a suspect in short stature.

B. thyroid hormone
Thyroid hormone plays a critical role in metabolism and skeletal growth. Its deficiency can cause growth delays.

C. sex hormones
Estrogen and testosterone influence growth plate closure and stimulate growth during puberty. Imbalance can lead to short stature or delayed puberty.

D. calcitonin
Calcitonin helps regulate calcium levels, but it has a minor role in growth. Deficiency or excess does not cause short stature.

A. UV radiation
UV exposure stimulates melanocytes to increase melanin production, leading to tanning and darker pigmentation.

B. pregnancy
Hormonal changes during pregnancy, particularly estrogen and MSH, can increase pigmentation, such as in melasma (the "mask of pregnancy").

C. melanocyte stimulating hormone increased number of melanocytes
MSH stimulates melanin production, not the number of melanocytes. The number of melanocytes remains relatively stable in most individuals.

D. increased production of dark melanin
More production of eumelanin (dark melanin) leads to increased pigmentation, seen in individuals with darker skin tones or increased melanin activity.