Hi, I have problem using the online form I have low vitamin D, ferritin and platelet count, I am also hypothyroid and probably have MS. What can be underlying cause? I am feeling very fatigued, have muscle aches, often feel thirsty and cold I tested negative on a standard celiac test, but I am on a plant based, gluten free diet anyway for the last 1.5 years. My ferritin during this time lowered from 30 to 18 and I have borderline low vitamin D soon after I stopped supplementation (20,000IU a day). In spite of eating plenty of fresh fruits and veggies I tested borderline deficient on Vitamin C in spectracell test. I was also borderline deficient in vitamin K, B5, zinc etc