Magnesium and vitamin B6 are often paired in food supplements because they work in related biochemical pathways. In this product, vitamin B6 takes part in protein and glycogen metabolism and works alongside magnesium in several biochemical pathways. Magnesium is involved in energy production, muscle function, and nerve signal transmission.
A combined tablet has a practical benefit: instead of buying and tracking two separate products, you get both nutrients in one coated tablet. That can be useful for people who want to simplify a diet-focused routine, especially during demanding periods when they are trying to cover a few nutrients without a large number of products.
That said, combining them in one product does not replace sensible dietary variety. A person still can take in magnesium from foods such as nuts, seeds, legumes, whole grains, and green leafy vegetables, and B6 from fish, poultry, potatoes, chickpeas, and bananas. A supplement is only part of the picture and is best used alongside regular meals rather than instead of them.