Vitamin D: The Sunshine Vitamin

by Dr. Sasha Marinaccio

As I sit on my patio admiring the warm summer sun, I can’t help but think of how nice it is to finally get some of the sunshine vitamin. Did you know that vitamin D is more than just a vitamin? Experts say it’s actually a hormone (1,4)! Vitamin D is a fat-soluble vitamin, which means it must be absorbed into our system with other fats if taken orally. While it is needed for calcium absorption and helps with bone, muscle and teeth development, the effects of vitamin D reach much further. Vitamin D is changed by the liver and kidneys into a steroid hormone that actually controls our genes and how they are expressed. That means that vitamin D has an impact on our DNA and almost every process in the body! It can affect our immune, respiratory, cardiovascular, musculoskeletal and nervous systems. There are two forms of vitamin D in our body: calcidiol (25(OH)-D) and calcitriol. Calcidiol is the form in which our body stores vitamin D; it is also the form we test for in the blood to determine if there’s a deficiency. Calcitriol is the active hormone.

In the past, a person was considered deficient if their blood levels were below 20ng/mL but we now know that number is too low. Levels need to be above 50ng/mL in order for our bodies to function properly (4). How do you become deficient? Deficiency most often occurs from a lack of sun exposure. If you have darker skin, you’re at a higher risk as it takes more sun exposure to produce adequate amounts of D due to a higher concentration of melanin in your skin. Breastfeeding mothers are at risk because they need to produce enough D for two people, as are those who are obese or elderly. So how do you know if you’re deficient? Because vitamin D is used by virtually every part of your body, there is no single symptom with which to diagnose. Common symptoms can include, but are not limited to: chronic pain, weak bones, depression, fatigue and a decreased immune system (4). Studies have even found correlations between low vitamin D levels and Multiple Sclerosis, finding increased incidences in northern latitudes where sun exposure is less. The only way to know if you’re truly deficient is for your doctor to order a blood test for 25(OH)-D. Always ask your doctor to tell you your level and don’t be afraid to ask for a copy of your bloodwork as some physicians are not aware that optimal levels are now higher than 50ng/mL.

There are two main ways to increase your vitamin D levels: sun exposure (from UVB rays) and supplementation. Vitamin D is measured in IU’s or international units. Sun exposure is the best way to get your D; the body can make up to 10,000IU as needed with full body, summer sun exposure in ~10-20 minutes, depending on a number of variables. The angle of the sun’s rays is an extremely important factor as it determines the strength of the rays. In the northern latitudes the UVB rays are not strong enough in the winter months or in the early morning and late afternoon hours. According to the US Naval Observatory, here in WNY the sun’s rays are strong enough from April 7th to September 6th in 2019 to make vitamin D (3). As mentioned before, skin type is also important; types IV-VI need longer exposure because melanin acts as a built-in sunscreen. Speaking of sunscreen, SPF 8 can block up to 95% of UVB rays and glass blocks 100% so if you’re covered in sunscreen or sitting behind a window, your body will not be producing vitamin D. Also, 40% of vitamin D production occurs in the trunk or mid-section of your body, so just having arm and legs in contact with the sun isn’t enough (4). The primary goal with sun exposure is to never get burned so err on the side of caution; UVA rays are the harmful ones that burn and increase your risk for cancer and skin aging. If you plan on staying in the sun after your exposure for D, you can then cover up or use sunscreens to protect your skin.

Oral supplementation is another way to increase your vitamin D levels. There are two types of supplements: vitamin D2 and D3. D3 is the naturally occurring form in our body and that is what should be taken to raise levels. How many IU’s you need to take daily depends on your weight and your blood levels. The current ADI (average daily intake) set by the Institute of Medicine is far too low at 600IU (4). Working with a physician and having your levels checked is the most exact way to determine how much you should consume. Without a blood test, a conservative, easy rule of thumb for adults is to take 20-25IU per pound of body weight. Most adults can safely supplement with 3,000-5,000IU daily. It is possible to reach toxic levels if using supplements; the body has a built-in safety mechanism and once optimal blood levels are reached, the skin stops producing vitamin D. When ingesting D however, you bypass this system. Rest assured, blood levels have to reach 150ng/mL to become toxic, a feat that would be near to impossible to attain with these recommendations. When in doubt, always consult your doctor
Cheers to summer and free vitamin D!

1) Dowd, James, MD. The Vitamin D Cure. John Wiley and Sons. 2008.
2) Mercola, Joseph, MD. Little Sunshine Mistakes that Can Give You Cancer Instead of Vitamin D. From:
3) US Naval Observatory. Sun or Moon Altitude/Azimuth table. From:
4) Vitamin D Council. From:

Office News

The office will be closed on Thursday, July 4th and will resume normal hours on July 5th.

We appreciate your patience and understanding as we continue to update our scheduling software in the coming months. As always, our doctors and staff are working hard to deliver exceptional care and service to you!

Recipe of the Month



This easy meal-prep honey-sriracha chicken dish, which can also be served as a main dish, is made on a sheet pan and comes together quick!

Prep Time: 10 minutes
Cook Time: 20 minutes


Olive oil spray
3 chicken breasts, diced into 1-inch pieces (24 ounces)
1 egg white, beaten
2 tablespoons corn starch
1 1/4 teaspoon kosher salt, divided
1 head broccoli, cut into small florets
2 teaspoons sesame oil
2 cups brown rice, cooked

2 tablespoons honey
2 tablespoons sriracha sauce
1 teaspoon seasoned rice vinegar
1 teaspoon sesame oil
2 scallions, sliced
1 teaspoon black and white sesame seeds, or as desired


  1. Preheat oven to 425F. Place the chicken in the egg whites, then in cornstarch and season with 3/4 teaspoon salt. Spray a large nonstick sheet pan generously with olive oil spray (so the chicken doesn’t stick) then add the chicken pieces, leaving room for the broccoli on one end. Bake in the oven for 10 minutes.
  2. Remove chicken from oven and flip, then add broccoli on the other half of the pan and drizzle with 2 teaspoons sesame oil, season with 1/2 teaspoon salt and pepper, to taste. Place back in the oven and cook until the chicken is cooked through and the broccoli is tender, about 10 minutes.
  3. Meanwhile, in a medium bowl whisk honey, sriracha sauce, rice vinegar, and sesame oil together until smooth. Add the chicken and toss in sauce to coat.
  4. Divide all the ingredients to 4 meal prep bowls, top with scallions and sesame seeds

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