As the days grow shorter and the weather turns colder, it’s not uncommon to feel a dip in energy and mood. But for some, this seasonal slump can feel more severe—impacting motivation, relationships, and overall well-being. If you’ve ever felt like the winter months cast a shadow over your life, you might be experiencing Seasonal Affective Disorder (SAD).
SAD is more than just “winter blues.” It’s a form of depression that follows a seasonal pattern, most commonly occurring in the autumn and winter months when shorter daylight hours and limited sunlight exposure can leave you feeling low, tired, and unmotivated.
In this comprehensive guide, we’ll explore various powerful functional medicine tools and strategies that can empower you to regain your energy, lift your mood and can conquer seasonal depression.
3% to 6% of the UK population experience SAD, with up to 20% experiencing milder forms of seasonal depression, often referred to as “winter blues.”
How To Recognise Seasonal Affective Disorder (SAD)
The symptoms of SAD can vary in severity but often mirror those of depression, including:
- Changes in appetite: Craving carbohydrates or overeating, often leading to weight gain
- Difficulty concentrating: Feeling mentally sluggish or unfocused
- Fatigue and low energy: Difficulty getting out of bed or maintaining energy throughout the day
- Loss of interest: Withdrawal from activities that are usually enjoyable
- Low mood: Persistent feelings of sadness, hopelessness, or irritability
- Sleep issues: Oversleeping or struggling to wake up in the morning
What Causes Seasonal Affective Disorder (SAD)?
SAD is often triggered by the lack of sunlight during the colder months which can cause low levels of vitamin D. Vitamin D plays a crucial role in mood regulation and this disruption has a knock on effect on:
- Circadian Rhythm: Reduced light exposure can throw off your internal clock, making you feel out of sync with your natural wake-sleep cycles.
- Serotonin Levels: Sunlight helps regulate serotonin, a neurotransmitter that boosts mood. Less sunlight can lead to lower levels, leaving you feeling down.
- Melatonin Production: Darker days increase melatonin, the hormone responsible for sleep, which can cause excessive fatigue.
Other contributing factors include nutritional deficiencies, chronic inflammation, and stress—all of which can be addressed through a functional medicine approach.
Who Is Affected By Seasonal Affective Disorder (SAD)?
Seasonal Affective Disorder (SAD) can affect anyone, but certain groups are more likely to experience it due to biological, geographical, and personal factors. Here’s a breakdown of who is most at risk:
- People Living Farther from the Equator: Those living in northern latitudes (e.g., Scandinavia, Canada, or northern parts of the U.S.) or southern latitudes are more likely to be affected.These regions have shorter daylight hours in the winter, leading to reduced sunlight exposure—a primary trigger for SAD.
- Individuals with a Family History of Depression: Having a family history of SAD or other forms of depression increases the likelihood of developing SAD as genetic predisposition can play a significant role in mood regulation.
- Individuals with Existing Mood Disorders: Those who have clinical depression, bipolar disorder, or anxiety disorders may be more vulnerable to SAD.
- Individuals with Low Vitamin D Levels: Low levels of vitamin D, common in populations with limited sunlight exposure, are associated with an increased risk of SAD. Vitamin D plays a key role in mood regulation and overall health.
- Women: SAD is diagnosed four times more often in women than in men, although men with SAD may experience more severe symptoms.
- Young Adults and Middle-Aged Individuals: SAD often first appears in young adulthood (late teens to early 30s) and tends to affect younger people more than older adults. Children and teenagers can also experience SAD, though it is less common.
- Shift Workers: People who work night shifts or irregular hours are more likely to have disrupted circadian rhythms and lower exposure to natural daylight, increasing their risk.
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How To Beat Seasonal Affective Disorder (SAD) With Functional Medicine
Functional medicine focuses on a personalised approach to healthcare, aiming to address the root causes of health issues rather than merely alleviating symptoms. For SAD, this means considering a range of biological, environmental, and lifestyle factors:
1. Get As Much Natural Sunlight As Possible
It is common to want to bunker down indoors during cold winter months, but make sure that you expose yourself to whatever daylight is available for at least 10-20 minutes outdoors each day, even if the weather is overcast.
2. Prioritise Nutrient Support
- Serotonin & Diet: Aim to increase serotonin levels through the consumption of foods rich in tryptophan, an amino acid that serves as a precursor to serotonin. Foods such as turkey, chicken, eggs, dairy, nuts, and seeds can support serotonin synthesis.
- Vitamin D: Known as the “sunshine vitamin,” vitamin D plays a key role in mood regulation. Low levels are common in the winter, so consider testing your levels and supplementing if necessary.
- Omega-3 Fatty Acids: Found in fatty fish, walnuts, and flaxseeds, omega-3s support brain health and reduce inflammation linked to depression.
- Antioxidant Foods: Fruits and vegetables can combat oxidative stress, which has been linked to depression. Berries, dark chocolate, leafy greens, and nuts are also excellent sources of antioxidants.
- B Vitamins: These are crucial for neurotransmitter production. A diet rich in leafy greens, whole grains, and legumes can help.
- Boost Gut Health: Your gut and brain are closely connected via the gut-brain axis. A healthy gut microbiome supports serotonin production, so focus on probiotic-rich foods like yogurt, kefir, sauerkraut, and miso, and reduce inflammatory foods like sugar, refined carbs, and processed snacks, which can exacerbate mood swings.
To find out more about personalised nutritional therapy, visit our How It Works page and book a free 15-minute Discovery Call with one of our expert practitioners to discuss your health concerns and goals.
3. Supplement With Vitamin D
Supplement protocols are often an important component of a personalised nutritional therapy strategy, helping to support areas of your diet where there is nutrient or vitamin deficiency. There are several supplements that can help enhance mitochondrial function:
Many people with SAD benefit from taking vitamin D supplements. A typical dose ranges from 1,000 to 4,000 IU daily, but testing your levels is ideal to determine the appropriate dose.
4. Optimise Your Sleep
Maintaining a consistent sleep schedule, minimising screen time before bed, and maximising natural light exposure during the day can support circadian health, help regulate melatonin production and improve sleep quality so that your mood during waking hours is more stable.
5. Practice Stress Management
Chronic stress can worsen SAD symptoms, so it’s important to manage your emotional health and carve out time for practices like mindfulness meditation, deep breathing, journaling and going for walks. Consistent practice, even if only for short periods of time, is key.
6. Move Your Body
Exercise is a natural mood booster. Regular movement increases endorphins and serotonin, helping to counteract the effects of SAD. Aim for at least 30 minutes of moderate exercise, such as brisk walking, dancing, or yoga, three times a week. If your exercise of choice can take place outside during the daylight hours, that is a bonus!
Viewing sunlight within the first hours of waking (as soon as you can, even if through cloud cover) increases early-day cortisol release (the ideal time for elevated cortisol) and prepares the body for sleep later that night. A morning spike in cortisol will also positively influence your immune system, metabolism and ability to focus during the day.
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How To Test For Seasonal Affective Disorder (SAD)
Functional testing can provide valuable insights into the biological and physiological factors contributing to SAD. Here are some tests that may be beneficial:
- Vitamin D Testing: Assessing serum levels of 25-hydroxyvitamin D can identify deficiencies that may be impacting your mood and overall health.
- Comprehensive Metabolic Panel (CMP): This panel evaluates kidney and liver function, electrolyte levels, and blood glucose, helping to identify potential metabolic issues contributing to depressive symptoms.
- Food Sensitivity Testing: Identifying food sensitivities can help individuals eliminate potential triggers that may contribute to mood swings or inflammation.
- Genetic Testing: Understanding genetic predispositions can help guide dietary and lifestyle interventions tailored to individual needs.
- Gut Health Testing: A stool analysis can identify dysbiosis or imbalances in gut microbiota, which can influence serotonin production and overall mental health.
- Hormonal Testing: Measuring hormones such as cortisol, oestrogen, and testosterone can help identify imbalances that may influence mood and energy levels.
- Thyroid Function Tests: Testing levels of Thyroid Stimulating Hormone (TSH), Free T3, and Free T4 can identify thyroid dysfunction, which is sometimes linked with depressive symptoms.
- Neurotransmitter Testing: Assessing levels of neurotransmitters (such as serotonin, dopamine, norepinephrine) can provide insights into mood regulation and biochemical imbalances.
To find out more about our range of tests visit our Functional Testing page or get in touch to speak directly with one of our expert practitioners.
YOUR HEALTH. YOUR CHOICE.
Conquering Seasonal Affective Disorder (SAD) starts with understanding the root causes and taking proactive steps to support your mind and body through the darker months. Whether it’s boosting your vitamin D levels with a personalised diet and supplement plan, or embracing lifestyle changes that nourish your mental health, small, intentional actions can make a big difference.
At Nutrition Diets Clinic, our functional medicine approach considers your unique genetic makeup, diet, environmental exposures, lifestyle factors, and health history:
1) Expert one-to-one therapy
2) Personalised nutrition and lifestyle plans
3) Easy, at-home functional testing
We offer thorough clinical assessment and therapy via convenient online consultations. Getting started is simple and free so why not take charge of your health today with our science-based strategies?
