Lifelines participants participating in general assessment 4A visit a location of their choice for a second time.
At the location, they undergo the following procedures:

• Fasting venapuncture to collect blood samples for blood analyses and storage (8+ years old).
• Handing in of 24-h urine samples for urine analyses and urine samples storage (18+ years old)
• Handing in of timed overnight urine samples for urine analyses and urine samples storage (8-17 years old).
• Handing in activity tracker.

4A Visit 2 is preceded by 4A Visit 1 (according to protocol).
4A Visit 2 is procedurally equivalent to 1A Visit 2, 2A Visit 2 and 3A Visit 2.