Spotlight Nutrient: Vitamin D
Vitamin D is known as the “sunshine vitamin,” but what do we do during winter when the sun is shining for – what seems like – only a few hours a day? How do we know if we have enough vitamin D, and why do we need it anyway?
Well, we need vitamin D for strong bones and a stronger immune system. It’s also important for muscles (including our heart), our brain, and has anti-cancer activity (1). During the summer months, we get some vitamin D from the sun shining on our bare skin. So, getting enough vitamin D can be tough during the winter.
Here’s what you need to know about Vitamin D:
- Recommendations for vitamin D are very conservative (super low). The Institute of Medicine recommends only 600 IU daily as the RDA (recommended dietary allowance) (2). Other experts say we need more (3).
- Doctors don’t normally check vitamin D levels! You can (and should) ask your doctor to check your vitamin D levels. They should be at least 30 ng/mL but really should probably be higher.
- Most foods don’t have enough vitamin D. Here are a few foods that have vitamin D in them: fatty fish (salmon, tuna, sardines), cod liver oil (gross, we know, but it’s a great source!), beef liver, and egg yolks.
- Supplementation may be necessary.
- Make sure to find a Vitamin D3 supplement (not D2). If your doctor has prescribed weekly vitamin D, then it’s probably vitamin D2. You want to take vitamin D3 on a daily basis instead of D2 on a weekly basis; it’s more effective at reaching and maintaining healthy levels (4). Before starting a supplement, make sure to talk to your physician because vitamin D does have a toxicity level.
Here’s a helpful guide for recommended intake:
|Recommended daily vitamin D for adults|
|Food and Nutrition Board (Institute of Medicine)||600 IU
800 IU (seniors)
|Endocrine Society||1,500-2,000 IU|
|Vitamin D Council||5,000 IU|
Vitamin D will help you keep your immune system strong through the winter, and you’re likely not going to get enough from food. Talk to your doctor or Registered Dietitians about this information to make sure you’re at your best this winter!
- Council TVD. What is Vitamin D? [Available from: https://www.vitamindcouncil.org/about-vitamin-d/what-is-vitamin-d/.
- Del Valle HB, Yaktine AL, Taylor CL, Ross AC. Dietary reference intakes for calcium and vitamin D: National Academies Press; 2011.
- Holick MF. Vitamin D and health: evolution, biologic functions, and recommended dietary intakes for vitamin D. Clinical Reviews in Bone and Mineral Metabolism. 2009;7(1):2-19.
- Logan VF, Gray AR, Peddie MC, Harper MJ, Houghton LA. Long-term vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over the winter months. The British journal of nutrition. 2013;109(6):1082-8.