The autumn leaves are falling, the days are shorter, and vitamin D is scarce. If you are living in Ireland like me, you know that sunshine will be a rare sight until March. So, this blog will discuss how we can get our Vitamin D without the sun and understand how important it is for our health and gut.
The Role of Vitamin D in Our Overall Health.
Vitamin D acts not only as a vitamin but also as a steroid hormone, orchestrating many key biological functions essential for overall health. It regulates calcium and phosphate levels in the blood, which are crucial for bone strength, muscle function, and nerve signalling, while also modulating insulin secretion, hormone synthesis, and the activity of numerous genes throughout the body.
Vitamin D further supports the immune system by having anti-inflammatory properties. It promotes the production of antimicrobial peptides, defenders that help shape the gut microbiome composition and enhance gut barrier protection. Vitamin D deficiency has been linked to increased inflammation, increased risk for digestive disorders, and a shift toward dysbiosis (an imbalance of the microbial compositions) in the gut.
Vitamin D and your Microbiome
Research studies in both animals and humans have shown that vitamin D promotes intestinal health and can change the composition of the gut microbiome and bacterial diversity. Research showed that exposure to sunlight or UVB light can modulate the gut microbiome. A recent study in 2024 showed that Vitamin D supplementation in healthy individuals increased the proportion of beneficial bacteria such as Bifidobacterium. A healthy gut promotes brain health, supporting cognitive function and emotional well-being.
How can we increase our Vitamin D levels
One easy way of increasing your Vitamin D during these dark months is through supplementation, and another is through your diet.
Though very few foods contain Vitamin D, the ones that do contain high amounts. For example, fatty fish, such as trout, salmon and cod liver oil, mushrooms exposed to the sun, fortified milk, sardines, eggs and tuna fish.
And of course, the best and most obvious source of Vitamin D is the sun, so whenever it is shining, make your best effort to get outside and soak it in, your mind and your body will be very happy you did.