Or gardens. They have the time to tend a garden and feed chickens and collect eggs.

I'm guessing a third party has a fat contract to provide bad food.

Sheriffs literally get to keep the money left over from the prison food budget in Alabama.

https://thinkprogress.org/in-alabama-prisons-the-less-sherif...

And more effective. IIRC, while vitamin deficiencies have been shown to cause problems, vitamin supplements haven't been shown to "fix" that problem [0]. You can't eat food with no nutritional value and then add the vitamins back in...that doesn't work. You need to eat food that has the vitamins to begin with.

[0] https://www.hopkinsmedicine.org/health/healthy_aging/healthy...

>> At least it is the common sense medical advice: "you don't need vitamins, just a healthy diet".

You also need sun (Vitamin D), which is not always an option for prisoners kept inside for 24 hours per day.

You can get vitamin D from your diet.

A typical American diet is deficient in Vitamin D if you live in the northern parts of the United States.

I can imagine that from a bureaucratic perspective, buying vitamin pills that have an extremely long shelf life is attractive and gives the veneer of paying attention to the nutritional health of inmates.