In adults ages 50+, the absorption of which vitamin typically increases due to reduced cutaneous synthesis and lower baseline status?

• A. Vitamin A (retinol)
• B. Vitamin B12
• C. Folate (vitamin B9)
• D. Vitamin D

Answer: (D)

Verified step by step guidance

1. Understand that the problem is asking about vitamin absorption changes in adults aged 50 and older, specifically which vitamin's absorption typically increases due to reduced cutaneous synthesis and lower baseline status.
2. Recall that cutaneous synthesis refers to the production of a vitamin in the skin when exposed to sunlight. Vitamin D is unique because it is synthesized in the skin through exposure to UVB rays.
3. Recognize that as people age, their skin's ability to produce vitamin D decreases, leading to lower baseline vitamin D levels in the body.
4. Because of this reduced synthesis and lower baseline status, the body compensates by increasing the absorption efficiency of vitamin D from dietary sources or supplements.
5. Conclude that among the options given (Vitamin A, Vitamin B12, Folate), vitamin D is the vitamin whose absorption typically increases in adults aged 50+ due to these physiological changes.