Even if he took a supplement, it's possible he wasn't absorbing it properly. Most supplement makers are reluctant to include high doses of Vitamin A in retinyl form, because it can cause liver damage. However, vitamin A in the form of beta-carotene has it's own host of absorption issues. In addition to being fat-soluble (i.e., must be taken with a sufficient amount of fat, or else it will compete with any other fat-soluble vitamins in the meal), it is also affected by high dosage of certain minerals. From ConsumerLab:

High doses of ferrous iron (but not ferric iron) or other minerals (calcium, magnesium, and zinc) from supplements may decrease the absorption of carotenoids, such as beta-carotene, lycopene and astaxanthin, from foods and/or supplements. This is likely due to a reaction between carotenoids and the divalent ions of these minerals, making the carotenoids less bioavailable (Corte-Real, Food Chem 2016; Biehler, J Nutr 2011). It is best to take carotenoid supplements at a different time of day than a supplement or meal containing large amounts of a mineral.

https://www.consumerlab.com/reviews/Vitamin_A_Retinol_Beta-C... (paid registration required)