A Functional Nutritionist’s Approach to Seasonal Blues & Seasonal Affective Disorder (SAD)

Understanding the Seasonal blues

When daylight saving time ends each Fall, the one-hour shift backward reduces the amount of light exposure most people receive in a 24-hour cycle. This also marks about two months since the last of the warm summer sunshine was part of our daily lives (especially here in Canada). If you feel a bit down this time of year, you're not alone.

Many people begin to experience "the winter blues," which often coincide with a drop in vitamin D levels, especially as the body's stores of vitamin D (with an average lifespan of around two months) start to wane. Low vitamin D, shorter days, and colder weather can all contribute to feelings of sadness and fatigue.

What is Seasonal Affective Disorder (SAD)?

SAD is a type of depression that occurs at specific times of the year, typically in fall and winter.

Symptoms can range from mild to severe and may include:

• Fatigue and low energy

• Persistent low mood and irritability

• Crying spells and emotional distress

• Difficulty concentrating

• Body aches

• Changes in sleep patterns and activity levels

• Cravings, particularly for carbohydrates

Root Causes of SAD

Several factors contribute to SAD, including:

1. Circadian Rhythm Disruption: Reduced sunlight during fall and winter can shift the body’s internal clock, affecting our sleep-wake cycles and leading to symptoms of depression.

2. Serotonin Deficiency: Sunlight affects serotonin, a neurotransmitter that regulates mood. Less exposure to sunlight can lead to reduced serotonin, contributing to SAD symptoms.

3. Melatonin Imbalance: Seasonal changes can disrupt melatonin, the hormone that regulates sleep, causing shifts in mood and energy levels.

4. Vitamin D Deficiency: Sun exposure is essential for vitamin D production, so levels often decline during the darker months. In fact, studies show that about half of all adults may be vitamin D deficient, which is closely linked to mood disorders like SAD.

5. Genetic Factors: Certain gene variants related to cholesterol synthesis and vitamin D metabolism may predispose individuals to low vitamin D levels, making them more susceptible to SAD.

Functional Nutrition Tips to Manage SAD

1. Eat a Colorful, Protein-Rich Diet

   Choose whole foods and avoid processed, high-sugar options that can exacerbate inflammation and elevate cortisol. High-quality proteins—such as grass-fed beef, poultry, eggs, and legumes—provide amino acids essential for the production of serotonin and dopamine, the "feel-good" neurotransmitters. Additionally, reducing inflammation from food sensitivities can have a positive impact on mood and energy.

2. Get Moving

   Exercise has been shown to boost endorphins and serotonin. Even moderate physical activity, like a brisk 30-minute walk, can help lift your spirits. If you’re up for it, try more intense activities like HIIT or even winter sports, which can be both invigorating and enjoyable.

3. Try Light Therapy

   Research supports the use of light therapy, especially low-intensity, blue-enriched white light at 750 lux, or standard bright light at 10,000 lux. Dawn-simulation lights, such as a Hatch alarm clock, may be particularly beneficial for those who oversleep or feel groggy in the mornings.

4. Soak Up Natural Sunlight

   While sunlight might be limited in the winter, making time for outdoor activities can make a difference. Exposure to sunlight—even in short bursts—boosts vitamin D production, enhances mood, and provides a chance to get some fresh air. Outdoor activities, like walking, hiking, or trying a new winter sport, can help you stay active and connect with nature.

5. Manage Your Stress

   Chronic stress can lower serotonin and contribute to feeling “stuck.” Incorporate stress-reducing activities such as meditation, yoga, journaling, or spending quality time with friends and family. Taking time for yourself to rest and recharge—even if it’s just cozying up with a good book—can also make a big impact.

6. Create a Winter Self-Care Ritual

   Create a simple, nourishing winter ritual that uplifts your spirits. This could be as simple as a weekly “spa night” at home, journaling with a warm cup of herbal tea, or a nature walk to soak in the season’s beauty. Rituals give us something to look forward to and provide moments of joy and connection, even during darker days.

7. Stay Connected

   Isolation can deepen feelings of depression. Even if winter makes socializing feel harder, reaching out to friends or family for regular catch-ups—even a quick call or text—can make a big difference in combating the isolation SAD often brings. If getting out isn’t an option, consider joining online communities or group classes for connection and support.

Supplement Suggestions for SAD Support

1. Vitamin D
   Testing and supplementation are key for optimal levels, especially in the winter. Low levels of vitamin D are strongly associated with depressive symptoms, so consider having your 25-OH D levels checked and working with a practitioner to determine the right dosage for you. Aim for a target range of 80–200 nmol/L, optimal is 125 and up.

   Tips for Incorporating Vitamin D Into Your Daily Diet

   1. Aim to eat at least two servings of fatty fish, such as salmon, mackerel, trout, and sardines, weekly. Grill or bake fish for a healthier cooking method than frying. 

   2. Include eggs in your breakfast, or add them to a salad. 

   3. Check food labels to identify products fortified with vitamin D

   4. Some mushrooms on the market have been treated with UV light to increase their vitamin D concentration (1).

   5. If possible, place mushrooms in direct sunlight before eating to help improve their vitamin D content. 

   6. Cod liver is an excellent source of vitamin D but can have an unpleasant taste. Try blending it into a smoothie or mix it with an acidic juice to mask the flavor.

2. B Vitamins
B vitamins are crucial for energy and mood regulation. If you’re on oral contraception, consider a B6 supplement, as contraceptives can deplete this vital nutrient. A high-quality B-complex is generally recommended for mood support and energy balance.

3. Saffron
Emerging research suggests that saffron may be beneficial for mood regulation, including SAD symptoms. Saffron appears to have a positive effect on brain chemicals like serotonin, making it a potential natural remedy for mild depressive symptoms.

4. Magnesium-Rich Foods or Supplements
Magnesium is known as the "relaxation mineral" and plays a vital role in mood regulation and stress resilience. Low levels of magnesium are linked with anxiety and depression, so increasing your intake through foods like leafy greens, pumpkin seeds, and avocados—or considering a magnesium glycinate supplement—can offer additional support during the winter months.

5. Omega-3 Fatty Acids
Omega-3s, particularly EPA and DHA found in fish oils, have been studied for their role in mood stabilization and anti-inflammatory effects. Omega-3 fatty acids help maintain healthy brain function and can be beneficial for those experiencing SAD. Foods like fatty fish (salmon, mackerel), walnuts, and flaxseeds are great sources.

6. Herbal Adaptogens
Herbs like ashwagandha and rhodiola are adaptogens, meaning they help the body adapt to stress. Ashwagandha has calming properties, while rhodiola is more energizing. Both have been studied for their effects on mood and resilience to stress, which can help those experiencing SAD.

7. Support Your Gut Health for Better Moods
Emerging research shows a strong connection between gut health and mood, referred to as the gut-brain axis. Ensuring good gut health—through fiber-rich foods, prebiotics, and probiotics (as tolerated)—can support serotonin production, as about 90% of serotonin is produced in the gut. Incorporating gut-supportive practices can indirectly improve mood and energy levels.

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With these dietary, lifestyle, and supplement strategies, you can support your body naturally and alleviate the winter blues. Small shifts, like choosing nourishing foods, getting some light exposure, and prioritizing self-care, can make a significant difference in how you feel throughout the season.

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