I saw Dr Michael Holick, an endocrinologist, earlier this year. He is very big on vitamin d and wrote “The Vitamin D Solution”.
Over the last two months I have been using a ‘Sperti Vitamin D lamp’ almost every other day. I just had my levels checked this week and they were a 41. I am very excited as this is the highest they have ever been. I have previously taken supplements for years, but because of malabsorption issues my levels stayed in the teens / low twenties.