Columbia, MD
Winter Fatigue in Columbia, MD: Daylight, Mood, and What Testing Can Tell You
Daylight in Columbia drops to about 9 hours 24 minutes at the winter solstice, and fatigue this time of year is common. Here is how to tell a winter slowdown from a treatable deficiency.
Reviewed by the clinical team at Zest Regen Health · November 8, 2026 · 7 min read
Content managed by Phil Kim, Lucky Consulting Group
In Columbia, Maryland, daylight shrinks from about 10 hours 26 minutes in early November to roughly 9 hours 24 minutes at the winter solstice, and the American Psychiatric Association estimates that about 5 percent of US adults experience seasonal affective disorder each year, with another 10 to 20 percent reporting milder winter blues. A November or December energy dip is common, but it can also mask low vitamin D, B12, iron, thyroid, or hormone changes, which is why the clinical team at Zest Regen Health evaluates persistent winter fatigue rather than assuming it is just the weather.
How much daylight Columbia loses in winter
Columbia sits near latitude 39 degrees north, so winter days are noticeably short. Sunlight drops from about 10 hours 26 minutes in early November to roughly 9 hours 40 minutes by late November, bottoms out at 9 hours 24 minutes around December 21, and only slowly lengthens in January. Less daylight means less morning light for mood, energy, and sleep timing, and it is one reason many people across the Baltimore-Washington corridor feel the winter slump.
Seasonal mood and energy: what the numbers show
Seasonal affective disorder affects about 5 percent of US adults in a given year, and milder winter blues affect a larger share, roughly 10 to 20 percent. SAD is about four times more common in women and becomes more common at higher latitudes. The key medical point: seasonal low mood and low energy are real, but they are not the only explanation for winter fatigue.
What can look like winter blues but is actually something else
- Vitamin D: sun-derived levels commonly drop through the darker months.
- Vitamin B12: fatigue, tingling, and memory trouble can appear in any season.
- Iron: low ferritin can cause fatigue, weakness, and poor concentration.
- Thyroid: an underactive thyroid slows energy, mood, and metabolism.
- Hormones: testosterone and estrogen changes affect energy year-round, not just in winter.
- Sleep: shorter days and less morning light can shift sleep timing and deepen fatigue.
None of these is a guess; each can be checked with a blood test. The difference between treating winter fatigue as just the season and treating the actual cause is a diagnostic evaluation.
What helps the winter slump
- Morning light: even 10 to 20 minutes of daylight, especially early in the day, helps regulate sleep and mood.
- Consistent sleep and meal times, since the darker season makes schedules drift.
- Daily movement, ideally outdoors when the weather allows.
- Appropriate testing when fatigue persists for more than a few weeks, so a vitamin or hormone deficiency is not missed.
If symptoms are severe, include sadness most of the day, or interfere with work and relationships, speak with a physician. Seasonal affective disorder and depression are treatable conditions, and the care team can help direct you to appropriate care.
When to get tested
A reasonable rule of thumb: if your winter fatigue has lasted several weeks, has not responded to light, sleep, and movement, or is joined by other symptoms such as tingling, hair changes, weight changes, or mood changes, that is a good time for a medical evaluation. A diagnostic panel at Zest Regen Health can check vitamin D, B12, iron, thyroid, and metabolic markers together so the picture is not fragmented.
See the Columbia clinic page for location and service area details
Learn how diagnostic wellness testing works at Zest Regen Health
Read about vitamin D blood testing and what levels mean
Read about iron and ferritin testing for fatigue
Read about cortisol testing and stress
Meet Dr. Francisco Ward, who evaluates patients at the Columbia clinic
Frequently asked questions
| Question | Short answer |
|---|---|
| How short are winter days in Columbia, MD? | About 9 hours 24 minutes of daylight at the winter solstice in late December. |
| Is it normal to feel tired in winter? | A mild energy dip is common, but fatigue that persists for weeks deserves a medical look. |
| What is the difference between winter blues and seasonal affective disorder? | SAD is a diagnosable form of depression tied to the season; winter blues are milder and affect more people. |
| Which blood tests help evaluate winter fatigue? | A diagnostic panel may include vitamin D, B12, iron, thyroid, and metabolic markers. |
| Should I start taking vitamin D on my own? | Not without knowing your level; the care team tests and doses based on your results. |
Next step
If the shorter days of a Columbia winter are taking more out of you than they should, a free 15-minute consultation at Zest Regen Health, 8860 Columbia 100 Parkway, Suite 216, Columbia, MD 21045, can help you decide whether testing is warranted. The team reviews your symptoms, history, and the right labs before any plan, and you can reach the clinic at (443) 917-6500.
Talk with our care team about this topic
A member of our clinical team can answer your questions at the Columbia, Maryland clinic. If Diagnostic Wellness Testing may be appropriate for you, the first step is a consultation.
Care at Zest Regen Health is physician-guided. Meet our physicians, who evaluate patients at the Columbia, Maryland clinic.