Hi all. 27yr old healthy female. Recently found out my vitamin d level was 19nmol. Ideal levels are around 50. Been suffering from extreme brain fog, constant haziness, blurred vision, problems concentrating and fatigue. Can vitamin d really be the cause of all this? And if so, how long did it take to build your levels up and feel better? Been given 50000 IU once per week for 6 weeks and have gone to the Caribbean for a month's holiday to try to get my levels up faster. Would love to hear how long it took you all to recover! My strength is back but the brain fog remains which is the most horrifying and distressing thing in the world. I feel like if I'm in a dream most of the time