What is the cause for painful joints?

Here are some things Vitamin C is responsible for:

• It's involved with collagen synthesis

• It can help lower inflammation 

• The need for vitamin C increases with stress (such as infection or surgery)

• Vitamin C is an antioxidant and a cofactor for opioids 

• Vitamin C is required for collagen  

• Vitamin C can't be absorbed in the presence of sugar 

If you're consuming sugar, or you're prediabetic or diabetic, that elevated sugar situation could prevent vitamin C from being absorbed. Vitamin C and glucose have a similar chemistry. In the presence of vitamin C and glucose, your body will always absorb glucose before the vitamin C. Insulin resistance could also cause a person to be deficient in vitamin C.  This could easily show up as joint pain.