Should we replace NAD+?

NAD+ levels decrease as we age and are associated with many hallmark signs of aging and are identified as a factor in a wide range of age-related diseases/dysfunctions such as decreased mood, reduced energy levels, diminished brain function, reduced muscle performance, weight gain, etc. Low NAD+ levels are one reason why we begin to feel the effects of aging and become more prone to age-related illnesses as the years pass by.