
Many people notice that their skin health is worse in the winter than it is in the summer. I’ve seen so many of my patients and clients experience this – they struggle to manage their skin condition, and it just gets harder as the winter goes on.
There are a number of different reasons why winter is tough on skin. One of the reasons is the lack of sunlight. The days are shorter – and this means lower vitamin D levels.
Why are vitamin D levels lower in the winter? What does this mean for your gut and skin health – and, most importantly, how can you address the problem?
Vitamin D and sun exposure
Vitamin D is a crucial substance that’s important in a wide variety of systems throughout the body, including the immune system, gastrointestinal system, and skin.
In order to exert its beneficial effects, vitamin D needs to be in its active form. A major part of the process of activating vitamin D occurs in the skin, and this involves ultraviolet (UV) light – which we get from sun exposure. If we don’t get any UV light on our skin, then our bodies can’t activate vitamin D.
In the winter, we’re exposed to far less sunlight than we are in the summer. For one thing, in many parts of the US, it’s cold outside in the winter – so we stay bundled up, which blocks the sunlight from reaching our skin.
However, even without this factor, we’d still activate far less vitamin D in the winter than in the summer. That’s because the intensity of the sunlight that reaches us is smaller in the winter. Even if you decided to brave the cold and go outside in short sleeves in the winter, you still wouldn’t be able to activate much vitamin D, because the intensity of UV light reaching your skin wouldn’t be enough.
The farther you are from the equator, the less sunlight reaches the earth’s surface in the winter. Here in the US, this means that the farther north you live, the more you’ll be affected by the lack of sunlight in the winter.
How vitamin D impacts your gut health
So it’s clear that we’re likely to have lower vitamin D levels in the winter. But what does that mean for your skin?
Over the past few years, researchers have increasingly been focusing on vitamin D as a key factor in a person’s overall health and well-being. While its effects on bone health were the first to be discovered, research is now finding that vitamin D actually impacts a huge number of different body systems.
Vitamin D is known to be necessary for the proper function of the immune system. Because of this, it can have a significant impact on your gut microbiome. In fact, vitamin D has been shown to be associated with increased levels of beneficial species and decreased levels of potentially harmful ones. I talk a lot about how your gut microbiome impacts your skin – it’s one of the most crucial factors for skin health. If you don’t have enough vitamin D, this can throw your gut microbiome out of whack.
In addition, vitamin D is important for the formation of a healthy intestinal barrier. The digestive tract needs prevent unwanted substances from making their way into the body’s tissues and the bloodstream. Vitamin D influences the body’s synthesis of certain proteins that are important for creating a healthy intestinal barrier. Without enough vitamin D, the barrier may not be able to stop allergens, toxins, or other unhealthy substances from getting through.
How vitamin D impacts your skin health
Besides altering your gut microbiome, vitamin D is also known to impact skin health in a number of other ways.
Because this vitamin affects function of the immune system, low vitamin D levels can potentially lead to increased inflammation throughout the body. This is probably why low vitamin D has been linked to flares of a number of common skin conditions, including acne, atopic dermatitis (eczema), rosacea, and psoriasis.
Vitamin D is also needed for normal cell division. Because of this, it’s important for healing and repair of the tissues of the skin. When the skin doesn’t have enough vitamin D, then it’s more likely to experience damage from environmental factors, which can lead to a skin flare. When a flare does occur, it’s also harder for the skin to heal the damage from that, so the flare might get worse and last longer than it otherwise would have.
In addition, vitamin D helps to regulate the activity of sebaceous glands, which produce oil. When the sebaceous glands are not regulated properly, then they may produce too much oil, which can lead to issues like acne. Or they may produce too little oil, which can cause the skin to dry out and affect its ability to form a protective barrier against environmental allergens and toxins.
Addressing low vitamin D levels in winter
It’s clear that vitamin D is crucial for your gut health and your skin health. And because sunlight is necessary for activating vitamin D, we tend to have much lower levels in the winter.
The intensity of the sunlight that reaches the earth’s surface is lower in the winter than in the summer. This means that, in many parts of the US, even if you could stand to be outside in the winter without covering up most of your skin, you still wouldn’t be able to activate much – if any – vitamin D.
Fortunately, there are ways to address this problem. It’s possible to get activated vitamin D through diet or supplements. Even though your body may not be able to activate enough vitamin D in your skin during the short winter days, you can still get your vitamin D from other sources, to support your gut and skin health.
The expert recommendation is to get at least 600 IU of vitamin D per day if you’re age 70 or younger. For older people, this increases to 800 IU. There are a few good natural sources of dietary vitamin D, including fish and egg yolks. Many foods also have vitamin D added to them, like milk and breakfast cereals.
Still, many people find it challenging to get enough vitamin D through diet alone, and it’s often helpful to take supplements. Some people choose to take supplements in the winter, but get vitamin D naturally from the sun in the summer. Others prefer to take vitamin D all year round.
There is a blood test that can check your levels of vitamin D. Some people prefer to do this test first, and only take supplements if their levels are low. However, most insurance plans won’t cover the test. It’s okay to take vitamin D without the test – it generally has a low risk of toxicity, so it usually won’t hurt you to take a reasonable amount, even if you haven’t proven that your levels are low. At the same time, side effects can occur if you take large amounts, so don’t go overboard – stick to the amount that’s recommended on the bottle, unless your doctor has personally advised you to take more.
While low vitamin D levels in the winter are definitely a huge factor, there are also other ways that winter can affect your skin. For example, the air is generally much drier in the winter, both indoors and outdoors. Most people also get far less exercise during the winter, which can impact your skin health as well as your overall physical and mental health. Addressing the need for vitamin D can make a huge difference for many people, but it’s also important to think about these other factors.
Winter can be a challenging season for health, but there are ways to mitigate the impact and keep your skin healthy throughout the season. There’s also a lot of magic to be found in winter – make sure to take some time to appreciate this, and to soak up the beauty that winter can offer.
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