By Dr. Justin Marchegiani
We call it a vitamin, but vitamin D is actually a hormone made by the body utilizing the sunlight that touches our skin. Conventionally, we thought vitamin D’s only purpose was to help with calcium and phosphorus regulation, but in the past ten to twenty years, we’ve discovered that vitamin D has so many other benefits, including regulation of over 800 different genes. It also benefits immune function, weight loss, and our sex hormones.
How Does Your Body Make Vitamin D?
Our skin contains precholesterol, a vitamin-D precursor. When the sun’s UVB radiation hits our skin, it combines with that precholesterol (this process is called synthesis) and makes vitamin D3. Vitamin D3 then passes through the liver and is converted into 25-hydroxyvitamin D (what we measure on lab tests). The 25-hydroxyvitamin D then passes through the kidneys and gets converted into 1,25-hydroxyvitamin D, or active vitamin D.
Vitamin D Functions in our Bodies
Balances the Immune System
The Journal of Immunology cites that autoimmune conditions are the number-three cause of death. It’s not the autoimmune condition, like lupus or Hashimoto’s, but it’s the inflammation from those conditions that predisposes us to cancer and heart disease and diabetes that lead to death.
Essentially, chronic inflammation is the underlying mechanism for all disease. So whatever we can do to reduce inflammation will help us feel better, live longer, and add more quality to our years. Making proper amounts of vitamin D will help us achieve this.
Leaky Gut and Autoimmune Disease
Leaky gut is often the first domino of autoimmune disease. When we have leaky gut, we’re predisposed to Hashimoto’s, an autoimmune condition of the thyroid. We also have type 1 diabetes and various neurological brain diseases, such as MS and Parkinson’s. Intestinal diseases, such as Crohn’s, ulcerative colitis, and celiac disease are included, too.
Vitamin D needs to be the first thing you look at right next to diet to help balance the immune system.
Stimulation of Sex Hormones
There are vitamin D3 receptors all around the body, especially in the sex organs. It is shown that vitamin D can actually stimulate the biosynthesis of sex hormones. In males its impact on testosterone can improve mood and muscle growth. In females, its impact on estrogen can improve neurotransmitter function (by helping with the reuptake of neurotransmitters, such as dopamine, GABA, and serotonin), which can allow us to feel better and more relaxed.
Promotes Weight Loss
High levels of insulin shuttle excess sugars and carbohydrates into our muscles and liver. And once those are saturated, it converts those extra sugars and carbohydrates to fat. High levels of C-reactive protein (CRP) increase inflammation, cortisol, and adrenalin, thus raising our blood sugar. Higher blood sugar, inflammation, and core diet increase insulin.
Vitamin D promotes weight loss by decreasing insulin levels. It also decreases CRP levels, reducing inflammation.
Vitamin-D Lab Testing
Vitamin-D levels are checked using a 25-hydroxyvitamin D test.
Traditionally, a deficiency in vitamin D was associated with rickets in children, a bone disease that causes bowing of the legs. The traditional lab values showed that if you were around the 20 range, you were safe from rickets.
Today we know we need vitamin D not just to prevent rickets but also for widespread benefits throughout our body. Newer lab ranges show above 30 is the minimum. Above 30 is about 30 to 100.
If you have an autoimmune condition, keep it closer to the 100 side because vitamin D has natural antibacterial benefits; it produces an enzyme called cathelicidin, which helps lower bacteria levels.
Some will use what’s called the Marshall protocol, where they’ll look at both 25-hydroxyvitamin D (calcidiol, stored vitamin D) and 1,25-hydroxyvitamin D (calcitriol, active vitamin D). However, research shows that 25-hydroxyvitamin D is the better way to test because stored vitamin D is a better marker than active vitamin D.
Optimal vitamin D is made by the sun, but in some regions (such as northern regions with latitudes in the 40 range) of the United States and at certain times of the year, optimal sunlight may not be an option. Even in sunny southern regions, if you don’t spend enough time outside, you won’t get adequate vitamin-D exposure.
Also, you have to expose your skin to the sun. If you’re just going out with T-shirt and shorts, you’re not getting enough skin exposure. You really have go out there with the goal of sunbathing, exposing as much skin as possible. If this much sun exposure isn’t possible, supplementation may be the key for you.
Vitamin D3 and vitamin D2 are the two supplementation options. Vitamin D3 is shown to absorb better, so that’s the one I recommend. Vitamin D taken on a daily basis seems to do better with vitamins K and A. So if you’re eating grass-fed meat or grass-fed butter, you will get adequate amounts of vitamins K and A.
If your vitamin D is super high and vitamins A and K are low, that’s not good. We want to make sure our diet has these vitamins to assure our vitamin D is effective.
Vitamin D3 comes in pills or a liquid. Some patients do really good with 5,000 units per day with the K2 in it, or if they’re deficient, we’ll go up to 20,000 units a day. This parallels with the 20,000 units you would naturally make with the maximum saturation of sun exposure.
Tips for Sun Exposure and Supplementation
- How do you know you’ve maxed your sun exposure? Your skin will start to look a little pink, not burned. That’ll be right around 20,000 units.
- Don’t shower right after you get sun. Wait at least an hour so the vitamin-D3 precursor hormone that’s on your skin absorbs into your bloodstream.
- The darker your skin, the longer you need to be in the sun. So if you’re African-American, for example, you will need more vitamin-D supplementation.
- If you get enough sun in the summer but not enough in the winter, supplement in the winter.
- If you’re in an area of the world where you never get enough sun, or you simply aren’t able to spend time sunbathing, supplement year round.
- If you’re low on the vitamin D scale, say around 20, supplement with 20,000 units the first month, cut it in half the second month, and cut it in half again the third month.
- If you have an autoimmune condition, supplement more.
- Get tested so you’ll know where to start.
Photo credit: Feature photo from Monarch Blog