VOA慢速英语:Low Levels of Vitamin D Might Hurt Your Brain

dementia – n. a brain disease that causes thinking problems

cognitive – adj. of, relating to, or involving conscious mental activities (such as thinking, understanding, learning, and remembering)

status – n. the position or rank of someone or something when compared to others in a society, organization, group, etc.

mild – adj. not strong in action or effect

impairment – n. a condition in which a part of your body or mind is damaged and does not work well

functioning – n. work or operation

decline – v. to become lower in amount or less in number : to become worse in condition or quality

adequate – adj. enough for some need or requirement : of a quality that is good or acceptable

supplement – n. dietary :  a product taken orally that contains one or more ingredients (as vitamins or amino acids) that are intended to supplement one's diet and are not considered food