Your Best Opportunity to Build Vitamin D
Summer in Alaska: Your Best Opportunity to Build Vitamin D Stores Naturally
For Alaskans, summer is more than a season of fishing, hiking, and endless daylight. It is also the most important time of year to build your body's vitamin D reserves.
After months of limited ultraviolet B (UVB) exposure during Alaska's long winters, summer provides a unique opportunity to naturally increase vitamin D production through sunlight, nutrition, and outdoor activity.
Why Vitamin D Matters
Vitamin D functions more like a pro-hormone than a vitamin (hormone support). It influences hundreds of biological processes throughout the body, including:
Immune function
Bone health and calcium absorption
Muscle strength and recovery
Mood regulation
Hormone production
Inflammation control
Cardiovascular health
Low vitamin D levels have been associated with increased risks of infections, osteoporosis, autoimmune conditions, depression, and metabolic dysfunction.
Unfortunately, vitamin D deficiency is common in northern climates where sunlight is limited for much of the year. But the good news is your body is designed to store it for the long winter months if you incorporate the right practices and nutrition.
How Your Body Makes Vitamin D
When UVB rays from sunlight strike the skin, a cholesterol-derived compound called 7-dehydrocholesterol is converted into vitamin D3.
The vitamin D3 produced in the skin travels to the liver and kidneys where it is activated into forms the body can use.
Unlike many nutrients that must be consumed daily, vitamin D can be stored in body fat, muscle tissue, and the liver for future use. This is why summer sun exposure can help support vitamin D levels throughout the darker months.
Think of Alaska's summer as your annual opportunity to fill your vitamin D "storage tank" before winter arrives.
Which Areas of the Body Absorb Sunlight Best?
Vitamin D production occurs in the skin wherever UVB light reaches it. Larger areas of exposed skin generally result in greater vitamin D production.
Areas that are commonly exposed during outdoor activities include:
Arms
Legs
Shoulders
Back
Abdomen
Research suggests that exposing larger surface areas of skin can produce significantly more vitamin D than exposing only the face and hands.
Interestingly, the face contributes relatively little to vitamin D production because it represents a small percentage of total body surface area. In addition, many people use sunscreen on their face year-round.
During Alaska's summer months, short periods of sun exposure to larger skin surfaces may help maximize vitamin D production while minimizing the risk of sunburn.
How the Body Stores Vitamin D
One reason vitamin D is unique is that the body can store it for later use.
After vitamin D is produced or consumed, it can be stored in:
Fat tissue
Skeletal muscle
Liver tissue
These storage sites act as reservoirs that release vitamin D when sunlight exposure decreases.
This storage mechanism is why vitamin D levels often peak at the end of summer and gradually decline throughout winter.
For Alaskans, maximizing healthy vitamin D production during summer can help support better levels throughout the year.
Alaska Salmon: Nature's Vitamin D Superfood
While sunlight is the primary source of vitamin D, food can also contribute.
Wild Alaska salmon is one of the richest natural dietary sources of vitamin D available.
A serving of wild salmon provides:
Vitamin D
Omega-3 fatty acids
High-quality protein
Selenium
Astaxanthin
These nutrients support immune health, cardiovascular function, brain health, and recovery from physical activity.
For Alaskans who spend their summers fishing, salmon offers a unique combination of outdoor sun exposure and one of the best vitamin D-rich foods available.
Can Cold Water Exposure Influence Vitamin D?
Cold water plunges, glacier-fed lakes, and ocean dips have become increasingly popular for their potential health benefits.
While cold water itself does not directly create vitamin D in the skin, emerging research suggests that cold exposure may influence several physiological processes related to vitamin D metabolism and overall health.
Potential effects include:
Increased activation of brown adipose tissue
Improved metabolic flexibility
Enhanced mitochondrial activity
Improved circulation
Reduction in inflammation
Some researchers have proposed that cold adaptation may influence vitamin D receptor activity and vitamin D utilization within the body. However, more research is needed before definitive conclusions can be made.
What we do know is that many traditional northern populations combined outdoor activity, cold exposure, and vitamin D-rich foods such as fatty fish to maintain health in challenging environments.
Practical Ways to Build Vitamin D This Summer
Spend time outdoors during peak daylight hours.
Expose larger skin areas when appropriate and safe.
Avoid sunburn while allowing reasonable sun exposure.
Eat vitamin D-rich foods such as wild Alaska salmon.
Stay active with hiking, fishing, biking, and other outdoor activities.
Consider checking your vitamin D levels through lab testing.
Work with a healthcare provider to determine whether supplementation is needed.
The Bottom Line
Summer in Alaska is more than a season of beautiful weather and outdoor adventure. It is your body's best opportunity to naturally build vitamin D reserves that may support health throughout the darker months ahead.
By combining sensible sun exposure, nutrient-dense foods like wild salmon, regular outdoor activity, and appropriate monitoring, you can make the most of Alaska's brief but powerful summer season.
References
Holick MF. Vitamin D Deficiency. New England Journal of Medicine. 2007;357(3):266-281.
Wacker M, Holick MF. Sunlight and Vitamin D: A Global Perspective for Health. Dermato-Endocrinology. 2013;5(1):51-108.
Cashman KD et al. Vitamin D Deficiency in Europe: Pandemic? American Journal of Clinical Nutrition. 2016;103(4):1033-1044.
Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. National Academies Press. 2011.
National Institutes of Health Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals.
USDA FoodData Central. Nutrient Composition of Wild Salmon.
Muscogiuri G et al. Vitamin D and Chronic Diseases: The Current State of the Art. Archives of Toxicology. 2017;91:97-107.
Sellers EA. Vitamin D and Indigenous Peoples in Northern Latitudes. International Journal of Circumpolar Health. 2016.
Tipton MJ, Collier N, Massey H, Corbett J, Harper M. Cold Water Immersion: Physiology and Potential Health Benefits. Experimental Physiology. 2017;102(11):1335-1355.