This study aims to examine the connection between the level of carotenoids in the skin and a number of immune related health parameters.

Inclusion Criteria:

• Willing and able to provide written informed consent
• Age 18-30 years OR 65 years and older
• Healthy individuals without uncontrolled medical conditions (over the counter inhaled and topical steroids allowed)
• Fiitzpatrick I-VI (all skin types)

Exclusion Criteria:

• Pregnant or breastfeeding
• uncontrolled medical conditions
• Skin conditions on the upper extremity that would interfere with skin measurements of carotenoid levels such as active atopic dermatitis or psoriasis
• Concurrent use of medications that affect the immune system, within 4 weeks of enrollment (eg. prednisone, biologics, methotrexate, rapamycin, prescription topical steroids, prescription inhaled steroids, others)
• Unable to follow study protocol

Healthy individuals who are either between 18 to 30 years old or over 65 years old.