Vitamin D: Why We Need “Sun Vitamins” All Year Round

During the winter months, when we spend more time indoors and the Northern Hemisphere is farther away from the sun with fewer hours of daylight, our body’s natural way of synthesizing vitamin D from sun exposure is highly compromised, which can lead to suboptimal vitamin D levels.

Of course, it’s especially vital to ensure your body has plenty of this sun vitamin for immune function at this time of year when colds, flus, and other viruses abound.

Indeed, vitamin D, which is considered a hormone, plays a critical role in immune response, calcium absorption and bone health, colon health, muscle movement, healthy nerve messaging, and many other functions throughout your body. Perhaps that’s why nearly every cell in your body has the vitamin D receptor.

What’s more, observational studies have shown an increased risk of a number of health issues that are associated with low levels of vitamin D – including low mood, mental health issues, poor cognitive function, being overweight, heart health problems, blood sugar issues, and even increased mortality, to name a few. However, on a brighter note, research suggests that a number of these risks can be mitigated with vitamin D supplementation.

When you can’t support your body’s ability to make vitamin D with adequate sunlight, vitamin D must come from the diet or through supplementation. Since dietary sources of vitamin D are limited (mostly found in fatty fish, mushrooms, or fortified cereals milk or juice), the supplementation is your best option.

Here’s what you need to know about the health benefits of vitamin D supplementation.

Sun Vitamins: What Are the Benefits of Vitamin D for Your Health?

Sun Vitamin | Vitamin D Health Benefits As mentioned above, your body is built to synthesize vitamin D. When your skin is exposed to the sun’s ultraviolet B (UVB) rays, it interacts with a protein in your skin, converting it into vitamin D3, the active form of vitamin D.

Many experts recommend spending 10-15 minutes exposing your face, arms, and legs without sunscreen to the sun two to three times a week. Keep in mind that fair skin more readily synthesizes vitamin D than darker skin, so darker skin may need slightly more sun exposure. Also, you don’t get the needed UVB light exposure through windows or in tanning beds.

Since sun exposure increases your risk of developing skin cancers, be sure to wear sunscreen or cover up immediately after getting the necessary exposure for vitamin D synthesis. If you choose to forgo sun exposure, you can get vitamin D from your diet and through supplementation.

While most people get enough sun exposure in the summer, interestingly, the 37th Parallel appears to be the demarcation line for inadequate levels of sun exposure in the winter months for optimal vitamin D synthesis. Living north of this Parallel increases your risk of vitamin D deficiency. (The 37th extends roughly from Santa Cruz, California, to the bottom of Utah and Colorado, to Hampton, Virginia).

Vitamin D Deficiency and Testing

Lack of sun exposure isn’t the only reason many people fail to get enough vitamin D. Surprisingly, breastmilk alone doesn’t provide adequate amounts of vitamin D for infants – supplementation or diet fortification is necessary. Elderly folks tend to be deficient in vitamin D as the body is less effective at both synthesizing and absorbing vitamin D as it ages.

Certain health issues can make vitamin D absorption difficult, such as digestive health problems. And since most people don’t consume enough fatty fish or vitamin-D fortified foods, that can cause deficiency too.

Research from the National Institutes of Health indicates that roughly 41% of Americans have insufficient levels of vitamin D.

The best and most accurate way to determine your vitamin D levels is to request a simple blood test. Vitamin D levels are often measured as part of a typical blood test. Just ask your doctor for a 25-hydroxyvitamin D (25 OH D) test. Vitamin D levels are measured in nanograms per milliliter (ng/mL).

The latest National Institutes of Health update on vitamin D sufficiency from September, 2022, states that vitamin D is, “required to maintain serum calcium concentration within the normal physiologic range for musculoskeletal health” and sites deficient and optimal (preferred) levels from The Endocrine Society, the National and International Osteoporosis Foundation, and the American Geriatric Society as <30 ng/mL and 40 to 60 ng/mL, respectively.

Taking these recommendations and others, here is a general guideline about what a test reading means:

  • Deficient: <30 ng/mL
  • Normal: 30-100 ng/mL
  • Low-Normal: 30-50 ng/mL
  • Optimal: 50-100 ng/mL

Vitamin D deficiency may have many health implications. In cases of severe vitamin D deficiency (levels are typically <20 ng/mL), research indicates a much greater risk of bone density loss, serious bone health issues, and fractures. In children, it can lead to serious bone health issues that cause bones to become soft and bend.

How to Supplement with Vitamin D

There are two forms of vitamin D supplements: D2 (ergocalciferol) and D3 (cholecalciferol). Although both forms may increase vitamin D in your blood, research shows that D3 is likely better absorbed and may raise it higher and for longer than D2. Hence, most experts recommend choosing vitamin D3.

The Endocrine Society recommends an intake of 400 to 1,000 International Units (IU) daily for infants under one year, 600 to 1,000 IU for children and adolescents from 1 to 18 years, and 1,500 to 2,000 IU for adults. The National Institute of Medicine has set vitamin D’s upper limit for daily intake at 4,000 IU. However, many experts suggest 2,000-5,000 IU of vitamin D3 per day for optimal health. Talk to your medical doctor to determine what is right for you.

Vitamin D is fat-soluble and should be taken with a meal or snack that includes some fat as it can increase absorption by roughly 30-50%. Some research indicates it’s best to take vitamin D in the morning as it can interfere with sleep by suppressing melatonin levels if taken late in the day or at night.

Of course, consistent supplementation yields the best results. Make vitamin D supplementation part of your daily routine!

At BrainMD, we’re dedicated to providing the highest purity nutrients to improve your physical health and overall well-being. For more information about our full list of brain healthy supplements, please visit us at BrainMD.

Kim Henderson