People love to talk about how you need this supplement and you need that supplement to be healthy, but it usually comes in the form of things like iron, calcium, omega-3s, and the other more popular ones. But what about vitamin D? Anyone ever tell you that you need to be taking vitamin D?
It’s arguably one of the most important supplements you can take, and while one of the easiest ways to get enough vitamin D is spending some time in the sun, you’d probably be surprised by the number of people who are low in it.
If you’re someone who isn’t quite sure why you need vitamin D, this article is for you. We’re talking about why vitamin D is a non-negotiable part of anyone’s diet (plant-based or not), and where to look for it if animal products are out of the picture.
What Is Vitamin D?
Vitamin D—sounds like just another vitamin like every other, right? Well, vitamin D is actually more than just a vitamin. It’s a fat-soluble prohormone steroid with endocrine, paracrine, and autocrine functions 1.
The endocrine functions of vitamin D are primarily targeted at regulating levels of calcium and phosphorus. Think of it this way: Vitamin D is the yin to calcium’s yang for bone health; they work together to gain tight control over serum calcium levels by regulating the uptake of calcium and phosphate from the gut or taking calcium from bones when serum levels fall.
The paracrine and autocrine functions of vitamin D, on the other hand, differ based on which type of cell is expressing the vitamin D receptors. Some of the most common functions are involved in cell proliferation, cell differentiation, and apoptosis (cell death).
The Role Of Vitamin D In The Body
With vitamin D receptors (VDRs) on virtually every cell in the body and has more than 1000 target genes 2, you know it plays some pretty important roles.
Boosts Your Immune System
One of the most well-known functions of vitamin D is its role in the immune system. It plays an essential role in both adaptive and innate immune responses, which are what control your immediate and long-term immunity 3.
Vitamin D deficiency has been linked to an increased risk of autoimmune conditions like rheumatoid arthritis, MS, diabetes, and IBD, as well as an increased susceptibility to infection 4; autoimmune diseases develop when the immune system becomes overactive and attacks its own tissues.
Regulates Your Mood
Ever notice that when the sun doesn’t shine, your mood is a little off? That’s because vitamin D helps to regulate mood.
Studies find that vitamin D supplementation effectively treats mood disorders like depression and seasonal affective disorder (SAD), which may be because VDRs are present in areas of the brain that regulate mood 5.
Studies also show that people with low vitamin D are at a higher risk for depression, which may be because of vitamin D’s role in regulating the synthesis of serotonin, the “happy hormone” 6.
Keeps Your Bones Strong And Healthy
Besides its role in immunity, vitamin D is best known for its role in bone health because of its ability to regulate the absorption of calcium and phosphate from the gut, both of which are required to maintain bone tissue.
It plays an essential role in the mineralization of the collagen matrix in bone to maintain health and strength 7. Without sufficient vitamin D, your body pulls calcium out of bones, which leads to an increased risk of osteoporosis and bone fractures.
And for women who’ve hit menopause, vitamin D is even more important because you no longer have enough estrogen to regulate bone density.
Here are some numbers to back this up: without adequate vitamin D, only about 10-15% of dietary calcium and 60% of phosphorus is actually absorbed. But when you have enough vitamin D, you can enhance calcium and phosphorus absorption by up to 40% and 80%, respectively 8.
Modulates Inflammation
In conjunction with its role in the immune system, vitamin D is also important for regulating the inflammatory response through modulating the production of inflammatory cytokines and inhibiting the proliferation of pro-inflammatory cells 9.
Controls Glucose
Last, we get to a hush-hush function of vitamin that most people aren’t aware of: regulating blood sugar. It helps to maintain proper glucose levels but also reduces the risk of insulin resistance, decreases triglyceride levels, and prevents weight gain.
Where To Find It
With all of that said, getting your hands on vitamin D-rich foods or a supplement is probably top of your list. But where vitamin D is concerned, there’s no shortage of sources if you’re consuming animal foods; it’s widely available in meats, seafood, and some dairy products. But if you’re following a plant-based diet, getting adequate vitamin D can be a bit more challenging.
For those of you that exclude animal products, the sun and supplements will be your best buds.
The sun emits UV rays that, when they hit the skin, stimulate the production of vitamin D3 from cholesterol—a steroid hormone that’s naturally present in your body and consumed through food sources. The sun’s UVB rays hit cholesterol in skin cells, which provide the energy required to synthesize vitamin D.
However, in order for vitamin D to be useful for the body, it has to be converted; directly from the skin or diet, it’s biologically inert and must be processed through the liver and kidneys to transform into the biologically active form that stimulates calcium absorption in the gut and allows it to perform its other functions 1.
Just 15-30 minutes of sunshine daily (maximum skin exposure) is enough to keep up your vitamin D levels, along with daily vitamin D3 supplementation (yes, both is better).
D2 vs. D3
When looking for a vitamin D supplement, there are two types you’ll find: D2 and D3. The former is the form often found in plant foods, while the latter is found in animal foods and supplements.
While vitamin D2 is good, studies find that a single dose of vitamin D3 was nearly twice as effective at increasing calcifediol levels at vitamin D2 10; D2 must be converted before being utilized by the body anyway, so you may as well take the active form, to begin with.
Final Thoughts
When looking for a vitamin D supplement, you want to make sure that what you’re buying is the best of the best.
Rather than sorting through hundreds of conventional supplements where the origin is dodgy, and you’re not sure what the other eight ingredients are, invest your money into something pure and effective.
Performance Lab NutriGenesis Multi for Men and Multi for Women are loaded with 17+ essential vitamins and minerals—including 125% of your RDA for vitamin D—designed to support overall health and hormonal balance.
NutriGenesis Multi is complexed with natural cofactors including probiotics, fiber, enzymes, and antioxidants that enhance nutrient bioavailability and health-supportive activity, so your body is getting what it needs to perform at its highest level.
References
- WZ Mostafa, RA Hegazy. Vitamin D and the skin: Focus on a complex relationship: A review.J Adv Res. 2015;6(6):793-804.
- S Sirajudeen, I Shah, A Al Menhali. A Narrative Role of Vitamin D and Its Receptor: With Current Evidence on the Gastric Tissues. Int J Mol Sci. 2019; 20(15):3832.
- M Hewison. Vitamin D and Innate and Adaptive Immunity. Vitamins & Hormones. 2011; 86:23-62.
- KL Munger, LI Levin, BW Hollis, NS Howard, A Ascherio. Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis.JAMA. 2006;296(23):2832-2838.
- DW Eyles, S Smith, R Kinobe, M Hewison, JJ McGrath. Distribution of the vitamin D receptor and 1 alpha-hydroxylase in human brain.J Chem Neuroanat. 2005;29(1):21-30.
- RP Patrick, BN Ames. Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior.FASEB J. 2015;29(6):2207-2222. doi:10.1096/fj.14-268342
- C Vitamin D and the immune system. J Investig Med. 2011; 59(6):881-886.
- R Nair, A Maseeh. Vitamin D: The “sunshine” vitamin.J Pharmacol Pharmacother. 2012;3(2):118-126.
- K Yin, DK Agrawal. Vitamin D and inflammatory diseases.J Inflamm Res. 2014;7:69-87.
- E Romagnoli, ML Mascia, C Cipriani, et al. Short and long-term variations in serum calciotropic hormones after a single very large dose of ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) in the elderly. J Clin Endocrinol Metab. 2008;93(8):3015-3020.
