Disclaimer: Human Health is not recommending any specific medical treatment for any particular symptom, nor providing any other medical advice. Always seek the advice of your doctor regarding any medical concern.

What is vitamin D and why do we need it?

Vitamin D is an organic substance that we need to maintain proper body function. It’s also called calciferol.

Many processes in the body need vitamin D. It’s particularly important for regulating calcium levels in the blood and bone. Vitamin D helps the gut absorb calcium, and is necessary for promoting bone growth and maintaining bone density.

A lack of vitamin D can lead to weak bones that break easily. Sufficient vitamin D intake can prevent bone disorders like rickets, osteomalacia, and osteoporosis.

What are the best sources of vitamin D?

We can make vitamin D in our bodies, but we need to be exposed to ultraviolet (UV) rays from the sun to do so. Some experts recommended that we get between 5–30 minutes of sun exposure at least twice a week to promote vitamin D production in the body.

However, it’s important to be mindful that too much sun exposure can cause sunburn and skin cancer, especially when it’s particularly hot or the UV rays are very high.

Fish liver oils and fatty fish like salmon, trout, tuna, and mackerel are natural sources of vitamin D, and it can also be found in small amounts in egg yolks, cheese, and mushrooms.

In the United States and Canada, most milk and infant formulas, as well as some plant milks like soy, almond, and oat milk, have vitamin D added to ensure appropriate intake.

For people deficient in vitamin D, dietary supplements of vitamin D may be recommended. Vitamin D2 and D3 supplements are commonly available at drugstores, but vitamin D3 may increase vitamin D levels more effectively.

It should be noted that excessive vitamin D intake can be toxic, and vitamin D supplements may also interact with certain medications, so you should consult with a healthcare professional before taking vitamin D supplements.

Who is likely to be vitamin D deficient?

Some groups of people are at higher risk of developing vitamin D deficiency. This may include:

• People with naturally darker skin color, as the pigment in their skin blocks effective UV ray absorption
• People who don’t spend a lot of time in the sun, or wear a covering such as a religious garment that limits their sun exposure
• People who have conditions like celiac disease, ulcerative colitis, cystic fibrosis, liver disease, or kidney disease, because it affects their ability to absorb and produce vitamin D

Tips for taking vitamin D

Vitamin D is a fat-soluble vitamin, which means it is more easily absorbed into the blood when taken with fatty foods. Examples include dairy products like cheese and milk, avocado, eggs, nuts, and fish.

Some people might find it hard to remember if they've taken their vitamins every day. The free Human Health app can send you notifications when it's time to take your vitamin D, and helps you keep track of which days you've remembered and if there were any days you've missed. You can also use the app to keep a record of how any symptoms you may be experiencing are impacting you.

Click here to download Human Health.

Resources

1. National Institutes of Health. Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals. Available at: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
2. UpToDate. Overview of vitamin D.
3. BetterHealth Channel. Healthy eating: Vitamin D.

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