I've taken D3 for years. It was one of the 1st things my GP checked, but my levels are fine, as are B12. Taking D3 is recommended by doctors and all the complimentary practitioners I have consulted including the chiropractor. I don't take probiotics as I have taken copious amounts in the past to no benefit , but at a great cost. This is because I have leaky gut and the gut environment does not support them. I am following a protocol to heal the gut ( which fell apart while on holiday, but things are settling now I am home). I'm determined to feel better. My diet allows room for naughty food in moderation. As I was told by the practitioner, that if your diet is too rigid, you eventually fall off the wagon. Wheat isn't a problem avoiding as I am intolerant to it, so I don't need will power! The reaction used to be immediate and very unpleasant!