By Dr. Rahim Habib ND

Over the past decade there has been an explosion of research into the multiple roles of vitamin D in the human body. It has long been common knowledge that you need vitamin D for healthy bones and teeth, particularly to prevent rickets in children. However, new findings show it has multiple roles, for your immune system, respiratory system, mental health, cardiovascular health, fertility, as well as optimal human functions. This article, will inform you of what you need to know about getting the right amount of vitamin D in the best ways.

Who Needs Vitamin D?

We all require vitamin D, from pregnancy throughout adulthood, it is simply fundamental to human health. Put it this way, every single cell in your body has a specific receptor to receive vitamin D, which means each part of your body has a role for vitamin D to accomplish.

For instance, recent studies from the University of South Carolina found that pregnant women who didn’t get enough vitamin D had a greater chance of developing gestational diabetes, preeclampsia, infections, required c-section, and were more likely to have their baby born before the due date.

At the other end of the spectrum, studies are starting to strengthen the concept that vitamin D has important roles for proper brain function, associating higher blood levels of vitamin D with better cognitive performance.

How Much Vitamin D Do I Need?

Different organizations and governments recommend different levels of vitamin D, so the recommendations will likely evolve over time. Currently, the basic guidelines are as follows: infants require 400-1000 IU (international units) daily; children and adults require 600-4000 IU daily. Most commonly, physicians tend to recommend 400 IU daily for infants and toddlers and 1000 IU daily for adults.

However, this may not be sufficient depending on your skin type, weight, lifestyle and where you live. As a naturopathic doctor, I have found that most adults require 2500-8000 IU daily to maintain an ideal level in the blood.

Factors Affecting the Level of Vitamin D in Your Body

Age: Older people don’t efficiently produce vitamin D in their skin, so their levels are lower when tested.

Weight: The heavier you are the more vitamin D you require as you may not activate vitamin D effectively as well.

Skin Type: Those who are fair-skinned and blue-eyed make vitamin D in their skin approximately 8 times more efficiently and easily when sun-exposed, compared to those who are darker-skinned. The more pigment you have in your skin, the harder it is to make vitamin D in your body.

Geography and Season: Those living closer to the equator have higher levels of vitamin D throughout the year, whereas those living in more Northern or Southern parts of the planet don’t make as much. It’s all about the level of ultraviolet B exposure from the sun, where and when there’s more UV-B, you make more vitamin D. For parts of the world that have distinct seasons with cold snowy winters, vitamin D will be much lower at these times.

Diet: Small amounts of vitamin D are found in egg yolks, beef liver, fatty fish, and fortified juice, fortified milks or fortified cereals and infant formula.

Other Factors: Being behind glass windows restricts UV-B exposure, reducing vitamin D; sun exposure in midday increases vitamin D production; little skin exposure to the sun, using sunscreen and high levels of air pollution reduce vitamin D production as well.

Are You Getting Enough Vitamin D?

The only way you will truly know if you have enough vitamin D is to get a blood test, so arrange a test through your primary care provider or nutritionist.

What are the Best Sources of Vitamin D?

Sufficient vitamin D levels require a combination of three sources.

Skin Exposure to the Sun: This is the most natural and physiologically appropriate way to get vitamin D. Your skin produces vitamin D after sufficient exposure to the ultraviolet-B (UV-B) rays from the sun. It’s important to note that you don’t need to burn or turn pink; you only need half of the daily sun exposure that would cause pink colouration on your skin.

The more skin you can expose the better. If you live in the Northern part of the USA or in Canada, you will need more sun exposure compared to those who live in Southern USA. As a guideline, your body makes about 10,000 – 25,000 IU of vitamin D in one sun exposure (1/2 way to getting pink), again, it would take longer if you are darker skinned. If you plan to be outdoors, when you reach half of your recommended sun exposure, then cover up with clothes or go indoors or in the shade, or apply a sunscreen.

Vitamin D Supplementation: This is the second best way to get enough vitamin D; follow the guidelines above and based on your blood test findings. Whether you take tablets, capsules or liquids, you will absorb vitamin D from your supplements. However, it will absorb best if you take your vitamin D with/near a meal.

Dietary Sources of Vitamin D: Alone, it is almost impossible to get enough vitamin D from eating a reasonable diet. However, the best non-fortified foods that contain vitamin D are fatty fish (especially salmon) and eggs. Fortified soy/rice/almond/dairy milk, juice and cereals are also a food source…see the labels for the amounts present in these foods.