Hi there, I have tested D levels at 16ng and Dr said 'a bit low so just just take an OTC Vit D'. Been reading your blog/forum of questions and it's rather low per your recommendations. Weighting 200lbs I suspect I need 2000 IU additionally to daily dose. Also, read some questions here that some posted with similar levels and their doctor ordered 50000IU weekly. Based on that I need 7100IU daily plus 2000IU additionally to compensate for extra weight. I have Calcium ascorbate and Vit D3 + K and Mag glycinate ready to go…would you comment if I am off. Thank-you for your feedback.