So they are saying that, for the same reasons grass fed field raised beef wins over industrially produced beef, that naturally assimilated nutrients from the source are much better for you than the industrially reproduced “assumed” nutrients of studied sources, in this case.. vitamin D3.. 

Yes. It works with everything. Green tea wins over caffeine pills (enough to convince me to stop taking pills and start drinking a load of green tea instead)Even with exercise: Treadmills don't activate your glutes properly as walking or running outdoors does (no wonder they all have flat bootys!)

The step mill will kill your legs / glutes.  Or, you could just do stair lunges, squeezing the glutes hard, up and down a flight (over and over) to failure.Cory

If you want to activate glutes, weighted hip thrusts or even the donkey kick are far more targeted than any lunges. But that's beside the point. What I'm saying is don't do your cardio on a machine if you want maximum benefits. Get outdoors.

LOL... never did the donkey kick or hip thrust exercises, yet my glutes are quite developed.I agree w/ the cardio advice.  Machines work, but it is healthier to spend more time outdoors.  😉I primarily rely on martial arts for my cardio, though.  Not outdoors, but not machines either.  Very dynamic, nonetheless, and teaches you to use your body in ways the average person has no clue about (esp. regarding balance, muscle distribution, muscle application, etc.).It’s funny about glutes.  One of the many kicks (the "back kick" or "Ushiro Geri") uses the force of contracting the glute of the kicking leg (plus a bit of lumbar / upper thigh) to deal the maximal damage.I am sure some of my muscular development is from Karate, not just weights.Cory