I can't find anything other than articles repeating this fact, and none of them say how much of them is in tallow. When I checked the USDA's site I got some numbers though:
For full table check
https://fdc.nal.usda.gov/fdc-app.html#/food-details/171400/nutrients
Per TBSP of tallow
Total lipid (fat) 12.8 g
Vitamin C, total ascorbic acid 0.00 mg
Vitamin B-6 0.00 mg
Vitamin B-12 0.00 µg
Vitamin B-12, added 0.00 µg Assumed zero (Insignificant amount or not naturally occurring in a food, such as fiber in meat)
Vitamin A, RAE 0.00 µg
Vitamin A, IU 0.00 IU
Vitamin E (alpha-tocopherol) 0.346 mg
Vitamin E, added 0.00 mg Assumed zero (Insignificant amount or not naturally occurring in a food, such as fiber in meat)
Vitamin D (D2 + D3), IU 3.58 IU Nutrient that is based on other nutrient/s; value used directly, ex. Nut.#204 from Nut.#298
Vitamin D (D2 + D3) 0.09 µg Nutrient that is based on other nutrient/s; value used directly, ex. Nut.#204 from Nut.#298
Vitamin D3 (cholecalciferol) 0.09 µg Nutrient that is based on other nutrient/s; value used directly, ex. Nut.#204 from Nut.#298
Vitamin K (phylloquinone) 0.00 µg Assumed zero (Insignificant amount or not naturally occurring in a food, such as fiber in meat)
It does have some vitamins, but it's so little I wouldn't consider it nutritionally significant.