The following is a contributed article detailing the benefits of Vitamin D. Vitamin D is one of the vitamins I take DAILY and absolutely swear by. If you’re looking for an essential vitamin for good health, this is the first one I, personally recommend. It’s also PERFECT for any of you who want to treat seasonal depression naturally. ~ Joi
Worried About the Dark Winter Days? This Vitamin Can Help You Combat the Winter Blues
by Kelin Marquet
As summer becomes a distant memory, temperatures plummet, and the days become shorter, it’s common to feel a shift in your mood and energy level. This lethargy and feeling of sadness is aptly named SAD, or Seasonal Affective Disorder (also referred to as “seasonal depression” or sometimes “winter blues”). It’s a recurrent mood disorder that can begin as soon as fall and last through the winter, and also includes symptoms like increased sleep, overeating, and carbohydrate cravings. (1)
Seasonal affective disorder usually occurs in winter, although it can also occur in the summer (especially for those living closer to the equator where hotter temperatures may mean less time outdoors)- the primary factor setting SAD apart from other types of depression is its cyclical, recurring nature that corresponds to a particular season.
Research has shown that we have a powerful ally in the fight against SAD: the sunshine vitamin, or vitamin D. Vitamin D is known for regulating calcium absorption and maintaining healthy bones and heart, but research shows it plays a crucial role in regulating mood.
How vitamin D improves mood
There are vitamin D receptors throughout the body, including within the brain. It plays an essential role in the synthesis of neurotransmitters, including both serotonin and melatonin, known as the happiness and sleep hormones, respectively. (2)
People with winter seasonal affective disorder tend to have 5% more SERT (a protein that helps transport serotonin) in winter than in summer. When SERT activity is high, serotonin is low, which then causes depression. In the summer, sunlight produces vitamin D, which keeps SERT levels low.
Similarly, SAD causes overproduction of melatonin. Overproduction of melatonin alone doesn’t cause seasonal depression, but it explains the accompanying lethargy most of those with SAD feel. (3)
Less exposure to sunlight means less vitamin D. Since vitamin D is linked to serotonin and melatonin activity, this decrease in vitamin D is believed to be a significant factor in the seasonal changes to these neurotransmitters in people with SAD.
Vitamin D deficiency and insufficiency are associated with depressive symptoms in all seasons. (4)
Sunshine and Vitamin D
Our skin produces vitamin D as a response to sunlight exposure. In theory, this should be one of the most accessible vitamins to get enough of, but in practice, almost half of the US population has a deficiency at the best of times. (5)
Many people mistakenly believe that you can make up for too little time in the sun through diet – even the best natural food sources of vitamin D (the best source is cod liver oil) are either under-consumed or contain far too little vitamin D to affect the body’s level. (6)
There are numerous reasons why we, as a population, do not get enough vitamin D from sunshine, including:
- Increasingly indoor lifestyles, including work and school schedules that require us to be indoors at “peak sun” (midday)
- Living in cities where buildings block sun exposure
- Air pollution
- Sunscreen use (important, but not helpful for vitamin D levels)
- Poor absorption or metabolic need for higher amounts (for example, in those with conditions like inflammatory bowel disease, obesity, or those who have undergone gastric bypass surgery
- High amounts of melanin in the skin (those with darker skin are especially susceptible to deficiency)
One other reason for low vitamin D production is that many of us live in areas far from the equator. People who live in northern hemisphere cities like Boston in the US, Edmonton in Canada, and Bergen in Norway can’t produce enough sunlight from vitamin D for 4, 5, or 6 months of the year, respectively. (7) In the absence of supplementation, they must depend on their body’s stores of vitamin D produced from the summer sun, but by late winter, many of these people are deficient. (8)
Benefits of Vitamin D
Mood isn’t the only thing affected by low vitamin D: it’s beneficial for everything from the heart to the immune system (is it a coincidence we consider the darker months “cold and flu season”?), to the brain and more.
Here are just a few of the areas vitamin D can help:
Bones and muscles: a meta-analysis (or study of studies) including more than 42,000 people over 65 found that 500-800 IU of vitamin D supplementation reduced fractures by about 20%. (9) It has also been thought to increase muscle strength by preserving muscle fibers.
Heart disease: the heart, like the brain, has vitamin D receptors. Vitamin D regulates the immune and inflammatory cells that can contribute to cardiovascular diseases like atherosclerosis. (10)
Cognitive decline: an analysis of over 427,000 white Europeans showed a 54% higher dementia risk in those with low vitamin D compared with those who had adequate levels. (11)
Immune system: many have hypothesized that the seasonality of cold and flu virus outbreaks is related to the lack of vitamin D in winter. A study on Japanese school children confirmed this: children who were given 1,200 IU of vitamin D per day decreased the rate of type A influenza by 40%. (12)
Low vitamin D is associated with numerous other conditions, including type 2 diabetes (13) and a lower survival rate from cancer. (14)
How to find a high-quality supplement
If you start to feel the winter blues and want to try a vitamin D supplement, here are a few tips to help you choose one that works:
Check for cGMP or NSF certification: Supplements in the US are not regulated, meaning the claims and claimed doses on the label may not match what’s in the bottle. cGMP and NSF represent strict manufacturing processes, and these companies typically have 3rd party testing to ensure purity and potency.
Use D3 form of vitamin D: Many supplements contain the D2 form, which is less effective than D3. D3 is the same form produced by sunlight. (15)
Combine it with K2: While vitamin D helps your body absorb calcium, vitamin K2 helps transport the calcium to your bones rather than soft tissues like arteries. It’s a good idea to take them together. (16)
Choose a supplement with minimal additives: Fillers, excipients, binders, and other additives often comprise the bulk of vitamin D supplements. Read the “other ingredients” on your supplement’s label to ensure you’re comfortable taking those additives.
Why Not Natural has two D3-K2 supplements that are third-party tested, contain minimal additives, and use the proper forms: both a USDA organic certified vitamin D liquid for flexible dosing and a high-dose vitamin D3-K2 capsule that’s carried in only organic spirulina and no other additives. You can also find their liquid vitamin D and vitamin D capsules on Amazon.
The daily dose you choose of vitamin D will depend on your current blood level and daily sunshine exposure. Always consult with your doctor before trying any new supplement.
(1) Seasonal affective disorder. A description of the syndrome and preliminary findings with light therapy
N E Rosenthal, D A Sack, J C Gillin, A J Lewy, F K Goodwin, Y Davenport, P S Mueller, D A Newsome, T A Wehr
(2) Effects of vitamin D on mood and sleep in the healthy population: Interpretations from the serotonergic pathway
Author links open overlay panel
Laura M. Huiberts, Karin C.H.J. Smolders
(4) Associations between Vitamin D Levels and Depressive Symptoms in Healthy Young Adult Women
David C. R. Kerr,a,* David T. Zava,b Walter T. Piper,c Sarina R. Saturn,a Balz Frei,d and Adrian F. Gombartd
(5) Prevalence and correlates of vitamin D deficiency in US adults
Kimberly Y Z Forrest 1 , Wendy L Stuhldreher
(7) Holick MF. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr. 2004; 79:362-71
(8) Holick MF. Vitamin D deficiency. N Engl J Med. 2007; 357:266-81.
(9) Bischoff-Ferrari HA, Willett WC, Wong JB, Stuck AE, Staehelin HB, Orav EJ, Thoma A, Kiel DP, Henschkowski J. Prevention of nonvertebral fractures with oral vitamin D and dose dependency: a meta-analysis of randomized controlled trials. Archives of internal medicine. 2009 Mar 23;169(6):551-61
(10) Norman PE, Powell JT. Vitamin D and cardiovascular disease. Circulation research. 2014 Jan 17;114(2):379-93.
(11) Navale SS, Mulugeta A, Zhou A, Llewellyn DJ, Hyppönen E. Vitamin D and brain health: an observational and Mendelian randomization study. The American Journal of Clinical Nutrition. 2022 Apr 22.
(12) Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. The American journal of clinical nutrition. 2010 May 1;91(5):1255-60.
(13) Mitri J, Pittas AG. Vitamin D and diabetes. Endocrinol Metab Clin North Am. 2014 Mar;43(1):205-32.
(14) Keum N, Lee DH, Greenwood DC, Manson JE, Giovannucci E. Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials. Annals of Oncology. 2019 May 1;30(5):733-43.
(15) Effects of High-Dose Vitamin D2 Versus D3 on Total and Free 25-Hydroxyvitamin D and Markers of Calcium Balance
Albert Shieh, Rene F. Chun, Christina Ma, Sten Witzel, Briana Meyer, Brandon Rafison, Leon Swinkels, Tonnie Huijs, Sam Pepkowitz, Brett Holmquist, Martin Hewison, and John S. Adams
(16) The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review
Adriana J. van Ballegooijen,
1 Stefan Pilz, 2 , 3 Andreas Tomaschitz, 4 Martin R. Grübler, 2 , 5 and Nicolas Verheyen 6