Your body makes vitamin D when your bare skin is exposed to the sun, about 10,000 units of vitamin D in 10 minutes of sun exposure, depending on time of the year and the amount of melanin in the skin.
According to Dr. Tim Arnold, family physician at Riverwood Healthcare Center, it’s good to get 10 minutes of sun exposure on bare arms and legs without sun protection products to get the vitamin D benefit. Then apply sunscreen to protect against sunburn and skin cancer.
“Without adequate sun exposure, children and adults require approximately 1000 to 2000 IU per day,” Dr. Arnold said. “From November through April, Minnesotans get almost no Vitamin D production from sunlight. Excessive exposure to the sun does not cause vitamin D intoxification because any excess production is destroyed by sunlight.”
Why do we need vitamin D?
Traditionally, vitamin D deficiency has been associated with rickets, a disease in which the bone tissue doesn’t properly mineralize, leading to soft bones and skeletal deformities. But increasingly, research is revealing the importance of vitamin D in protecting against a host of health problems.
Research studies have documented a much higher prevalence of heart disease, cancer, multiple sclerosis and autism among people who live in the northern United States, Canada and Scandinavian and northern European countries compared to those who live in warmer climates with more sun exposure.
Specifically, research documents a strong connection among people with low levels of vitamin D and colon, prostate and breast cancers, along with a corresponding higher death rate. Studies have shown a 70% reduction in breast cancer among women who have adequate levels of vitamin D.
Vitamin D helps the body absorb calcium and keeps our bones healthy. It also helps maintain optimal phosphorous levels in the blood. Together with calcium, vitamin D also helps protect older adults from osteoporosis. A broader overall benefit is that vitamin D promotes a healthy immune system for protection from many diseases.
People with a vitamin D deficiency are more likely to have a severe or critical case of COVID-19, according to a recent study in Israel. Vitamin D can help the body fight COVID infections by bolstering the immune system to better deal with viral pathogens that attack the respiratory system.
Although it’s called a vitamin, it really acts more like a hormone, according to Dr. Arnold.
Vitamin D levels
The body stores vitamin D in the form of serum 25-hydroxy vitamin D. The normal range is 30 to 80 nanograms per milliliter (ng/mL). A lower level indicates vitamin D deficiency, which you should discuss with your healthcare provider.
How can you find out your vitamin D level? The most accurate way to measure how much vitamin D is in your body is the 25-hydroxy vitamin D blood test. Then you and your physician can decide what combination of diet, smart sun exposure and supplements will work best to get you to an optimal level for your own good health.
If you’re buying a Vitamin D supplement, make sure the label says “D3”. D3 is the compound formed in the skin when exposed to ultraviolet-B rays.
Vitamin D is a powerful tool to support good health—and it’s inexpensive. The cost is less than a penny a dose.
Getting “D” in your diet
Because very few foods contain vitamin D naturally, it’s nearly impossible to get the amount your body needs in your diet. Fortified foods provide most of the vitamin D in the American diet. Almost all milk is fortified with vitamin D, but dairy products made from milk, such as cheese and yogurt, may not be not fortified. Check labels for vitamin D content. Breakfast food cereals often contain added vitamin D, as do some brands of orange juice, yogurt and butter or margarine.
Fresh salmon has the highest content at 600-1000 IU of vitamin D3 for 3 oz, compared to 300-600 IU vitamin D3 for canned salmon. Other oily fish high in vitamin D include sardines, tuna and mackerel. A teaspoon of cod liver oil has about 400 to 1,000 IU’s. One whole egg has 20 IU of vitamin D2 or D3.
On average, mother’s milk contains little vitamin D as most mothers are vitamin D deficient. Infant formulas typically are fortified with 100 IUs per 8 oz.
To learn more on vitamin D and diet, go to the National Institutes of Health website at http://ods.od.nih.gov/factsheets/vitamind/#h3