Vitamin A includes many related compounds called retinoids. Vitamin A from animal foods is known as retinol, while vitamin A from fruits and vegetables is known as provitamin A carotenoid, including beta carotene, alpha carotene, and beta cryptoxanthin. These forms are converted into retinol in the body. Other carotenoids include lutein, zeaxanthin, and lycopene. Vitamin A derivatives are essential for growth and maintenance of epithelial (skin) cells, as well as inhibit growth-stimulating signals [Mongan NP & Gudas LJ, 2007 as cited in i]. The below study explores the association between vitamin A intake and cutaneous squamous cell carcinoma (SCC) risk, which is a common type of skin cancer in those with fair skin.
Journal: JAMA Dermatology
This year prospective cohort study included over 75,000 female participants (mean age = 50) and over 48,000 male participants (mean age = 54) from the Nurses’ Health Study and the Health Professional Follow-up Study, respectively. Participants completed a questionnaire on medical history and lifestyle, with follow-up twice per year since 1976 (Nurses’ Health) and 1986 (Health Professional) until 2012, including report of new diagnosis of SCC. Participants also completed a Food Frequency Questionnaire nearly every 4 years.
The authors found:
1. An association between higher intake of total vitamin A, retinol, and certain individual carotenoids (beta cryptoxanthin, lycopene, lutein, zeaxanthin) and lower risk of SCC
2. A more prominent inverse association in those with moles and those with burn/blistering sunburns as children
3. No association between higher intake of vitamin A from supplements and risk of SCC
For the Patient and Caregiver
Include foods with vitamin A into your regular eating pattern. Some foods to consider are: sweet potato, winter squash, kale, collard greens, carrots, salmon, and cod liver oil. A good tip to keep in mind is to look for orange, yellow, and dark green vegetables to obtain higher levels of vitamin A. Additionally, because vitamin A is a fat soluble vitamin, pair with fat (such as sweet potato with olive oil and spices) to increase absorption.
For the Healthcare Team
Encourage intake of both plant and animal sources of vitamin A. Advise patients that many animal sources of vitamin A are high in saturated fat (meat, cheese, cream), so to limit these to only a few times per week. Remind individuals of the importance of sunscreen use year round and to schedule annual dermatology visits for examination of skin and moles.
[i] Kim J, Park MK, Li W, Qureshi AA, & Cho E. (2019). Association of vitamin A intake with cutaneous squamous cell carcinoma risk in the United States. JAMA Dermatol. doi: 10.1001/jamadermatol.2019.1937.