Blood Test Analysis: My Experience with Vitamin D3 Supplements

For those who stay out of the sun, vitamin D3 supplements are a must. (Photo by respres)

In my last post, I analyzed my cholesterol levels and revisited the debate surrounding saturated fat. The main reason I went to have a blood test, however, was to see how my vitamin D levels were.

I have learned about the importance of vitamin D only quite recently. After some reading, I decided to start taking vitamin D3 supplements. For the first couple of months, I took 2,000 IU (equal to 40 mcg) daily, which is fairly conservative and often the minimum dose recommended by people who've done their homework. Conventional wisdom on the other hand still sees 400 IU of vitamin D2 as sufficient, even though it produces serum levels that are way too low for optimal health.

About one month before the blood test I increased my intake to 5,000 IU per day. Since I still had plenty of 2,000 IU capsules left, I took 2 capsules every other day and 3 every other day, thus averaging 5,000 IU. Since the serum half-life of vitamin D is quite long, this shouldn't make any difference.

After supplementing with 2,000 IU vitamin D3 for a few months and then increasing to 5,000 IU for a month, my serum 25-hydroxyvitamin D levels were 113 nmol/L, or about 45 ng/mL. This is considered to be within the optimal range, which is 32-100 ng/mL (link).

Considering that

1. Most people have suboptimal serum levels of 25-hydroxyvitamin D
2. Most foods provide only small amounts of vitamin D
3. I live in the north and avoid the sun,

I think it's safe to say that the fact my serum levels are within the optimal range is mainly due to supplementation. I'm also fairly certain that prior to starting taking supplements, my levels have been even lower than average – that is, I've been deficient in vitamin D for most of my life.

Whether or not you enjoy the sun, I encourage you to get your vitamin D levels checked. And if you have already done that, feel free to post your results in the comments. I'm currently collecting data from other people to do a post on how people's serum levels have varied with and without vitamin D3 supplements.

For more information on vitamins, sun and health, see these posts:

Topical Vitamin C for Skin: Re-examining the Case
How to Get Natural Sun Protection by Eating the Right Foods
Sesame Seeds Increase Absorption of Vitamin E Tocotrienols by Up to 500%
Lutein for Skin Elasticity, Hydration and Photo-Protection – Experiment Begins