It can be normal to feel tired and worn out during cold winter months. Current safety measures of staying indoors more often, coupled with increased stress and dreary weather can cause fatigue, low immunity, muscle pain, and feelings of depression or exhaustion. These can all be symptoms of seasonal affective disorder, or “SAD.” But for some, they could simply be an indication of a Vitamin D deficiency. We sat down with GHC-SCW Dietitian Julie McLaughlin, MS, RD, CD, CDE to get the facts on the importance of Vitamin D.
Why do we need Vitamin D?
Vitamin D is necessary for many key functions of a healthy body. Your immune system needs it to fight off bacteria and viruses and to help your body absorb calcium. Your muscles need it to move, and to help your nerves carry messages between your brain and body.
How much Vitamin D should we get every day?
The amount of Vitamin D you need depends on your age. For children ages 1-13, teens 14-18, and adults up to the age of 70 the recommendation is 15 mcg (600 IU). For adults aged 71 and older, 20 mcg (800 IU) is recommended. It’s important to note that some people need more or less depending on their medical history.
What foods contain Vitamin D?
Very few foods naturally contain Vitamin D. Almost all of the United States milk supply is fortified with about 3 mcg (120 IU) of Vitamin D for each 8 oz. glass. Many plant-based alternatives such as soy milk, almond milk, and oat milk are fortified as well. Vitamin D is added to many breakfast cereals and to some brands of orange juice, yogurt, and other food products. Fatty fish (trout, salmon, tuna) are among the best natural sources of Vitamin D. A 3 oz. portion of salmon contains 11 mcg (450 IU) and 3 oz. of canned tuna contains 4 mcg (150 IU) of Vitamin D. While they are not naturally high in Vitamin D, some farmers expose their mushrooms to UV light which increases the Vitamin D content.
Are there other ways to increase my exposure to Vitamin D?
Your body makes Vitamin D when bare skin, with no sunscreen applied, is exposed to the sun. However, clouds, old age, skin with increased melanin, and Wisconsin weather reduces the amounts your body can naturally make. While sunscreen limits Vitamin D production, it’s important to use sunscreen with an SPF of 15 or more when you’re outside for more than a few minutes. Unfortunately, sunlight through a window does not result in Vitamin D production.
Should I take a Vitamin D supplement?
You should always check with your primary care provider or pharmacist before starting any supplements as some of them may interact with certain medications. Keep in mind, the supplement industry is not regulated by the FDA which means there isn’t a standard check on most vitamin contents or amounts. If you are interested in taking vitamin supplements, make sure to only use brands that have the USP Seal on the label. These are certified by a third-party lab to verify they contain what the label claims.
What happens if you are Vitamin D deficient?
It’s very common for people to be Vitamin D deficient year-round in Midwestern states like Wisconsin. In children, Vitamin D deficiency can cause bones to become weak and soft. In teens and adults, it can lead to a disorder that results in bone pain and muscle weakness. Long term shortages of Vitamin D and calcium can lead to osteoporosis. Some studies have shown a link between low blood levels and an increased risk of depression. Vitamin D is important for a healthy heart, blood vessels, and for normal blood pressure.
How do I know if I am Vitamin D deficient?
There is a blood test that your provider can prescribe that measures the amount of Vitamin D in your blood. About 25% of Americans have low Vitamin D levels. That number is most likely higher during winters in Wisconsin. If you suspect your level may be low, talk to your provider about testing your blood.