Vitamin D deficiency has become very fashionable. It doesn't take a smart clinician as it is simply included in your routine CBC that you would take at the doctors office. Vitamin D is a vitamin that your body would naturally produce as you produced melanin upon sun exposure. Being in Phoenix that might not be the source of your moderate deficiency.

I also did a course of Vitamin D for a moderate deficiency. I'm in the more northern climes and might not really see the sun for the majority of the year plus we are always taught to slather on sunscreen to prevent burning, so exposure is in bits and pieces.

At 56 I'm not crazy about you taking 5,000 International Units (IU) each and every day. Again, it is fat soluble and 5,000 IU might be a bit much to your 56 year old liver. I did my supplement as 5,000IU every other day. When I was done with that bottle I went with a 2,000IU dose that I took once daily then did a 1,000 IU bottle as my 3rd. Each bottle was 100 capsules, so that was nearly a year of vitamin D supplementation.

My levels returned to normal after this although I'm sure they returned sooner than the nearly a year of supplementation. After that I get a small amount in my multi. Vitamin D levels have also dropped in the general population because the very foods that are rich in Vitamin D --> tuna, salmon, dairy, orange juice, cereals, cheese, egg yolk we have been told to eat in moderation... and of course the moderate exposure to the sun.

Vitamin D is said to regulate mood, and although I'd like to think I am fairly well balanced, we can always use some help.

Spring Valley brand is a very highly rated vitamin as far as dissolution and absorption goes.

I do take issue with taking 5,000IU daily, as I try to limit higher level supplements going through my liver.

It's hard to quantify the effects of the correction, but I was able to correct it simply. Now my Vitamin D and B12 levels (my other small cross I had to bear) are in line.