Vitamin D is an essential nutrient, that is integral to our health. Yet vitamin D deficiency is one of the most common deficiencies we see today. So, what is the big deal about vitamin D and why is it so hard to get?
Vitamin D is an essential nutrient responsible for:
- calcium absorption
- bone mineralization, bone growth and remodelling
- balance of minerals in the body
- reducing inflammation
- supporting immune function and many more
But unlike the rest of the nutrients, it is impossible to get enough of it from food. Instead, the key ingredient to getting enough vitamin D is sunshine. This nutrient is produced in kidneys and the skin and this process is regulated by sunlight. There are very few naturally occurring sources of vitamin D, which include salmon (600 IU of vitamin D per serving), sundried shitake mushrooms and fortified products, such as milk, which barely offers 100 IU of vitamin D per cup. The sun offers up 10,000 IU of vitamin D within 5 – 50 minutes, depending on one’s skin tone (the darker the skin, the longer the exposure required.) Once the body receives 10,000 IUs it stops making vitamin D.
Most of the Vitamin D is produced during the summer months, which means we are limited to only 2-3 months of exposure. People living closer to the equator, in areas with sunnier, warmer climates are less likely to experience vitamin D deficiencies. There are other factors that make getting enough vitamin D challenging:
- During those summer months, when we have our best chances of getting in some vitamin D, the best hours are from 9am-3pm, which for many people are typical working hours.
- While using sunscreen protection is important, using sunscreen 8 SPF or higher will inhibit the production of vitamin D.
- Darker skin pigments tend to have lower levels of Vit D as the pigment in their skin acts as a shade and makes it harder for the skin to synthesis the energy from the sun.
- Age, as we get older our skin becomes thinner, which also makes it more challenging to produce enough vitamin D.
- Glass and plastic barriers also block the UVB rays that allow for vitamin D production.
There are numerous challenges to obtaining adequate vitamin D levels, which is why often vitamin D supplementation is recommended between the months of October in May (in Ontario), as during these seasons, you cannot obtain any vitamin D even when you are in the sun, because the UVB rays are falling at a different angle.
Some common symptoms of vitamin D deficiency, that we are currently aware of, include:
- bone discomfort or pain (often throbbing)
- increased risk of fall and impaired physical mobility
- muscle aches
- muscle weakness
- symmetric low back pain in women
Lack of vitamin D can also worsen symptoms of seasonal affective disorder (SAD) and can affect cognition, contributing to symptoms like brain fog.
The recommended Vitamin D doses are:
- 600 IU per day for adults
- 800 IU per day for older adults (60+)
- 2000 IU per day for those with osteoporosis
- 400 IU per day for breastfed infants
These recommendations vary based on other factors, such as blood test results, medical history and other factors. So, this is a good time of the year to have a conversation with your doctor, dietitian or a local pharmacist about your vitamin D needs.