Older people suffer more from deficiencies of than young people do.

Vitamin D and Vitamin B12

Explanation: Vitamin D deficiency could be caused by lack of exposure to sunlight. This is prevalent in adults who may be weak and thereby unable to get themselves exposed. Loss of appetite is also common among the elderly due to build up of hormones which decrease appetite and fewer neurotransmitters which stimulate appetite, leading to inability to consume certain foods or consuming inadequate amount of such food.

Vitamin D

Explanation:

As people age, synthesis declines

Drinks little or no D-fortified milk

Gets no exposure to sunlight