Thanks for sharing and for your question, Georgios. Actually, I half expected you to ask that question. I know that you are very health conscious and also very well informed. I was wondering whether you might take a Vit-D supplement. So, here we are. I can't judge whether you are Vit-D deficient. Only a blood test can tell you that. An optimal serum level of 25-hydroxyvitamin D (25OHD) for bone health is above 20 ng/ml (50 nmol/liter). This threshold reflects a consensus view rather than a biological need. If blood levels fall below this concentration, daily supplementation with a small dose of vitamin D 800 IU will suffice to bring it up again. However, my guess is that you might not fall into the deficiency, or even insufficiency, range. Your diet and your sun exposure (I assume you reside in Greece?) should be sufficient to keep your 25OHD level above the 20ng level. Whether higher doses of supplementation are safe longterm is a question that hasn't been answered yet.