Ladies, listen up! We all love that warm, sun-kissed glow you get after a long summer full of sunshine.

But if you aren’t aware, there’s another incredibly important thing that happens when you sit in the sun... synthesize VITAMIN D.

And why do you need vitamin D? Well, you’re about to learn about all the benefits in the following article.

Before we get ahead of ourselves, you must understand that virtually every single cell in the body contains a receptor for vitamin D.

So, as you can probably guess, it’s an important vitamin. 

And if you feel you're not getting your daily dose, you'll find it on the ingredients list of a good ultramodern multivitamin for women, along with other essential nutrients including folate and zinc.

Here’s some of the important functions of vitamin D:

  • Promotes calcium absorption from the gut
  • Maintains calcium and phosphate concentrations
  • Bone growth and bone remodeling
  • Reduces inflammation
  • Regulates immune function
  • Involved in glucose metabolism
  • Encodes proteins regulation, cell proliferation, differentiation, and apoptosis

But in terms of why you need it, how are these for some good reasons? We'll give you 6, to be exact...

It Boosts Your Immune System

When the weather gets colder, panic mode inevitably sets in as you aim to kick your immune system into top gear and prevent yourself from those pesky colds. But aside from getting plenty of rest and staying hydrated, how do you do that? With vitamin D.

The impact on your immune system is one of the most well-known functions of vitamin D because of its ability to modulate both the innate and adaptive immune system, specifically antimicrobial activity and antigen presentation (innate) and T and B lymphocyte function (adaptive) responses [1].

Vitamin D deficiency is associated with an increased presence of autoimmune diseases like rheumatoid arthritis, MS, diabetes, and IBD, as well as increased susceptibility to infection [2].

It Keeps your Bones Strong and Prevents Osteoporosis

If you’ve ever fractured a bone before, you probably know just how important bone strength is. And regardless of age, that never changes.

So, why do your bones love vitamin D so much? Because it controls the absorption of calcium in the small intestine and stimulates osteoclast differentiation and calcium reabsorption of bone and also promotes mineralization of the collagen matrix in bones to keep them strong [3].

A deficiency of vitamin D decreases calcium absorption from the intestines, causing an increase in the production of osteoclasts, which then leads to mobilization of calcium from the bone.

When there is not enough vitamin D circulating in the blood, osteoclasts release enzymes to breakdown the bone matrix, ultimately releasing calcium and other minerals into circulation and decreasing bone strength [4]. By doing so, the risk of osteopenia and osteoporosis increases.

It Regulates Your Mood

Have you ever heard of seasonal affective disorder (SAD)? It’s what many people experience during the winter when the weather is cold and days of sunshine are few and far between.

But why does this happen? Because of low vitamin D, which shows you how vital vitamin D is in regulating mood!

Research shows that vitamin D is a powerhouse for treating symptoms of depression and potentially certain other mental health conditions. This may be because vitamin D receptors are present in areas of the brain responsible for regulating mood [5].

Also, a 2013 study found that people with low levels of vitamin D had a higher risk of depression [6].

And if that’s not enough, vitamin D also plays a role in regulating the synthesis of serotonin, your happy hormone. This is because vitamin D is a crucial regulator of brain serotonin synthesis through tryptophan hydroxylase-2 (TPH2) [7].

So, a vitamin D deficiency may leave you more susceptible to low mood and other mood imbalances.

It Keeps Your Glucose Levels in Check

You may not know this, but as you age, glucose metabolism becomes a little whack. While it’s not a necessary component, it is common to the aging process.

Maintaining adequate vitamin D levels not only helps to regulate your blood sugar, but it also reduces the risk of insulin resistance, decreases triglyceride levels, and reduces weight gain.

And research suggests that a Vitamin D deficiency may be detrimental to the production of insulin.

In human studies, vitamin D is positively correlated with insulin sensitivity, which is mediated directly through the availability of vitamin D receptors in various body tissues, and indirectly through alterations in calcium levels [8].

Other studies have also shown an inverse relationship between vitamin D status and impaired glucose tolerance, insulin resistance, and diabetes.

And it May Help Control your Weight

If you’re looking to lose a few pounds, vitamin D may help you! 

Along with keeping your glucose levels in check, which prevents fat and weight gain, studies show that supplementation of vitamin D, when combined with exercise and mild caloric restriction, could help to lower inflammation levels and boost fat loss.

How? Vitamin D’s role in increasing calcium also stimulates apoptosis (cell death) of adipocytes, commonly referred to as fat cells.

It does this by activating the sympathetic nervous system, which, in turn, boosts thermogenesis and fat oxidation.

What’s more, it also acts on the GI tract to increase fecal fat excretion and increase the release of GI hormones that regulate appetite [9].

It’s Essential for Pregnancy

If you’re looking to start a family at some point, start with getting your vitamin D levels in check. Research shows that Vitamin D plays a significant role in fertility by acting on both the ovaries and the endometrium.

Concerning the ovaries, vitamin D can enhance ovulation by altering AMH (anti-Mullerian hormone) signaling, increasing FSH sensitivity, and increasing progesterone production [10]. Women with adequate vitamin D levels also appear to have better rates of implantation.

Poor fetal bone health can be a consequence of an insufficient intake of vitamin D during pregnancy, as well as an increased risk of preterm birth, gestational diabetes, pre-eclampsia, and bacterial vaginosis [11, 12, 13, 14, 15].

How Do You Get Enough Vitamin D?

SUNSHINE! Sun exposure is the best and easiest way to boost your vitamin D levels.

If you’re lucky enough to have warm weather year-round, 15-30 minutes daily with no sunblock, no sunglasses, and as much skin exposure as possible will maintain vitamin D levels. 

However, for people that aren’t so fortunate to have sun all year round, vitamin D supplements in the form of D3 is your next best option, which is widely available nowadays.

Consuming an abundance of vitamin D-rich foods is also a great way to keep your levels up. Coldwater fatty fish like salmon, sardines, mackerel, and herring are some of your best sources of vitamin D, but it’s also concentrated in liver, cheese, and eggs [4].

If you’re sitting there thinking, “okay well I don’t eat meat, where can I get vitamin D?” supplementing with vitamin D3 is probably your best bet. This is solely because the vitamin D found in plant foods is in the form of D2, which is not as effective at raising blood levels of vitamin D as D3.


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