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Integrative Health

Dreading Early Sunsets? Here’s 1 Easy Habit That Can Protect Your Mood

Molly Knudsen, M.S., RDN
Author:
Molly Knudsen, M.S., RDN
October 13, 2026
Molly Knudsen, M.S., RDN
Registered Dietitian Nutritionist
By Molly Knudsen, M.S., RDN
Image by Clique Images / Stocksy
October 13, 2026

Fall back is quickly approaching. In fact, the return to standard time aligns with Halloween this year—making for an extra-spooky weekend. This change will push sunsets into the 4 and 5 p.m. hour for folks across the country (a 4:37 p.m. sunset for me in Boston) and drastically affect mood. For many, this marks the start of the spiral towards the winter blues.

So what can you do to protect yourself from feeling too down during this time? Take advantage of the early morning light, keep a consistent sleep schedule, and still go out and enjoy your evenings. 

You should also pay attention to (and improve) your vitamin D status. 

How does vitamin D & mood?

Vitamin D is best known for its role in bone health. But the nutrient also interacts with the brain, where vitamin D receptors are found in several regions involved in mood regulation, including the hippocampus, prefrontal cortex, and hypothalamus.

Researchers believe vitamin D may influence mood through several pathways, including its role in neurotransmitter activity. Vitamin D helps regulate processes involved in the synthesis and metabolism of serotonin, dopamine, and norepinephrine, chemical messengers that play a role in mood and emotional well-being.*

In addition, vitamin D may help with:*

  • Stress response: Vitamin D may help modulate the HPA axis, which coordinates the body's hormonal response to stress.
  • Neurotrophic support: Vitamin D may influence proteins such as BDNF and NGF, which help maintain neuron health and function.

The risk of being vitamin D deficient

So, it’s no surprise that a systematic review of 15 studies1 found consistent evidence that vitamin D status and overall mood are closely linked.

So, it’s no surprise that a systematic review of 15 studies1 found consistent evidence that vitamin D status and overall mood are closely linked.

According to researchers, sufficient vitamin D levels promote a healthy mood, while a vitamin D deficiency (below 20 ng/ml from a vitamin D blood test) contributes to the risk of low mood and poor mental well-being2.*

And vitamin D deficiency is quite common (yes, even coming off of summer!). It’s estimated that 29% of U.S. adults are clinically deficient3 in vitamin D and 42% are insufficient3. The only way you can tell where your levels stand is to get a blood test (via a healthcare provider or one of these at-home options). You want your levels to be at least 30 ng/ml, but many health experts agree that truly optimal levels are around or above 50 ng/mL. 

How to raise your vitamin D levels

The best way to raise your vitamin D (or maintain optimal levels) is with the support of a high-quality supplement. 

mindbodygreen's vitamin D3 potency+ was specifically formulated to be effective at raising stubbornly low vitamin D levels.* Each gelcap offers 5,000 IU of the optimal vitamin D3 (better than D2 supplements) sustainably sourced from organic algae. Vitamin D is a fat-soluble vitamin and is best absorbed in the presence of fat, which is why each capsule also contains a mixture of avocado, flaxseed, and olive oil.

But taking a vitamin D supplement does not raise your levels overnight. Rather, it can take anywhere from 8 to 12 weeks—and sometimes longer depending on the supplement dose—to start to see a change on your vitamin D blood test. Meaning. Consistency and time are important to see benefits. 

The takeaway

Darker days, longer nights, and cold weather are a perfectly destructive recipe for developing a low mood this winter. Having optimal vitamin D can help counter that. 

As it can take a little time to correct insufficient or deficient vitamin D levels, now's the time to get your vitamin D levels checked and start a supplement.

Nervous about your sleep with the time change? Try making this sleepy girl mocktail as part of your nighttime routine. 

If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.