Well,the low readings here are not unusual to NeuroTalk. In fact the websites (both grassrootshealth and Vitamin D council) both have statistics to show many people in US and elsewhere are very low.

One thing to consider if you decide to do high dose Vit D3 (more than 2000IU daily) is not to take alot of calcium. One cardiologist has a blog, and he is recommending not to go over 600mg a day of calcium in supplement form. In fact I don't take any!
Vit D increases calcium absorption from food, and it is possible with a good diet to no longer need high dose calcium in supplement form while on high dose Vit D 3 supplementation.

Both my husband and I take 5000IU daily from Sept, to July. Once we are outside in the sun more, I stop ours. It has made a huge difference for both of us as far as mental and physical stamina, and neither of us gets colds or sick anymore too.

It is recommended for patients with sarcoidosis to not take supplements of D without a doctor's supervision. This is because the research into this uncommon condition of inflammation is not well founded with Vit D issues. The Marshall Protocol and all that. (you can Google it if you haven't heard of it but I bet most of you have!