Everything you need to know about Vitamin D

By: Nada Eltom

Vitamin D, often called the sunshine vitamin, is a vital nutrient that supports numerous functions in your body.

From strengthening bones to boosting immunity, enhancing mood, and even protecting your heart, its benefits are vast and well-documented. This guide will walk you through everything you need to know about vitamin D, including its role in your health, how it’s synthesized, top dietary sources, and ways to address deficiencies. Let’s explore how this powerhouse vitamin can help you thrive.

1-Overview:

Most commonly known as the sunshine vitamin, vitamin D plays a major role in many of your body’s processes. (5)

Vitamin D is fat soluble compound responsible for increasing intestinal absorption of calciummagnesium, and phosphate. In humans, the most important compounds within this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). (1)

Vitamin D also regulates many other cellular functions in your body. Its anti-inflammatory, antioxidant and neuroprotective properties support immune health, muscle function and brain cell activity. (2)

Your body produces vitamin D naturally when it’s directly exposed to sunlight. You can also get vitamin D from certain foods and supplements to ensure adequate levels of the vitamin in your blood. (3)

2- Vitamin D synthesis

The epidermal layer of human skin synthesizes vitamin D when exposed to UV radiation. In the presence of sunlight, a form of vitamin D3 called cholecalciferol is synthesized from a derivative of the steroid cholesterol in the skin. The liver converts cholecalciferol to calcitriol, which is then converted to calcitriol (the active chemical form of the vitamin) in the kidneys. (4)

3- Some benefits of vitamin D 

Vitamin D helps your body function in multiple ways. 

  • Strengthens the Bones

Vitamin D is known for its bone-building and strengthening powers. The nutrient       helps the body absorb calcium for improved bone and muscle health. Calcium wouldn’t be able to do its job without vitamin D. The two nutrients together can also help prevent osteoporosis. This condition occurs when a person has weak, brittle bones. (6)

  •  It may help boost your mood

Low vitamin D levels have been linked to increased incidences of depression. This doesn’t necessarily mean that vitamin D deficiency causes depression but it’s clear that vitamin D supports brain health, in general.

“Older adults with lower vitamin D levels seem to experience faster memory loss than those who have healthy levels. Also, those with lower vitamin D have an increased risk for depression, and those who have depression seem to show a lower vitamin D level,” (5)

  • Supports Immune system function

Vitamin D is involved in immunity through several mechanisms and plays a role in regulating both the innate and adaptive immune response in the body. The innate immune is the body’s non- specific, first line of defense against foreign pathogens. Research has also found that vitamin D builds immunity against flu and colds. Vitamin D deficiency is most prevalent in the winter when cold and flu season peaks. Clinical trials have demonstrated that increasing vitamin D level has been shown to decrease incidents of influenza (7)

  • It might lower the risk of heart disease

Heart disease remains the number one cause of mortality in the nation, therefore it is imperative to do your best to maintain a healthy heart. Like skeletal muscles, heart muscles are regulated when vitamin D interacts with vitamin D receptors in the cells. When it comes to blood pressure, Vitamin D regulates blood pressure by acting on endothelial cells and smooth muscle cells. Not only that, it has a major role in helping to strengthen muscle fibers, protecting the heart as a result. Additionally, vitamin D may help keep arteries flexible and relaxed, also benefiting blood pressure. Although a deficiency has been linked to various cardiovascular risk factors, more studies are needed to establish the protective role of vitamin D on the heart. (8)

  • It might give you an energy boost

If you are constantly fatigued, getting more vitamin D might give you the energy boost you need. Vitamin D has an impact on the function of the mitochondria, the part of a cell that produces energy. A 2016 study found that vitamin D treatment significantly improved fatigue in healthy people with vitamin D deficiency.  (8)

4-Symptoms when vitamin D id low (11)

Most people with vitamin D deficiency are asymptomatic. However, if you’re exhausted, your bones hurt, you have muscle weakness or mood changes, that’s an indication that something may be abnormal with your body.

Symptoms of vitamin D deficiency may include:

  • Fatigue
  • Not sleeping well
  • Bone pain or achiness
  • Depression of feeling of sadness
  • Hair loss
  • Muscle weakness
  • Getting sick more easily
  • Loss of appetite
  • Pale skin

If these symptoms sound familiar, it’s time to see a medical professional. They do a blood test to check your vitamin D levels to see if they are within normal range.

5-Top Vitamin D Food Sources (8)

By now you know the importance of getting enough vitamin D in your diet for better health. Here are the top vitamin D rich foods you’ll need to add to keep your levels up to par:

  • Cod liver oil (34 mcg per 1 tablespoon serving)
  • Oily fish: Salmon, sardines, herring, and mackerel are all good sources of vitamin D, Salmon (14.2 mcg per 3 oz serving)
    • Mushrooms (9.2 mcg per ½ cup serving)
    • Fortified milk (2.9 mcg per 1 cup serving) and milk alternatives (2.5-3.6 mcg per 1 cup serving)
    • Fortified orange juice (2.5mcg per 1 cup serving)
    • Fortified cereal (2.0 mcg per 1 cup serving)
    • Beef liver (1.0 mcg per 3 oz serving)
    • Egg yolks: A serving of two eggs contains 8.2µg of vitamin D which is 82% of the recommended dietary intake. Eggs are one of the highest food sources of vitamin D. (10)

Vitamin D absorption 

  • Eating foods with healthy fats, like avocado, nuts, or full-fat dairy, can help your body absorb vitamin D. (9)

6-Vitamin D Supplements vs. Food

When it comes to vitamin D, there are a few foods that naturally contain it, although some foods are fortified with vitamin D, like orange juice, milk or some cereals. It’s always best to get your nutrients from food first as it’s more potent, but sometimes it can be challenging to rely on food alone. Healthcare providers may recommend a supplement to help you meet your daily vitamin D requirements and ensure your levels are within normal range. 

7-How much vitamin D should you get each day?

It can be tricky to figure out how much vitamin D you need since different health organizations recommend different amounts. Your age plays a major role in how much you need and other instances (like breastfeeding or pregnancy) may require more of the nutrient, so it’s best to discuss your specific needs with a medical professional.

References:

  1. https://www.healthline.com/health/food-nutrition/benefits-vitamin-d
  2. https://courses.lumenlearning.com/wm-biology2/chapter/vitamin-d-synthesis/
  3. https://www.prevention.com/health/a35183225/vitamin-d-benefits/?utm_source=google&utm_medium=cpc&utm_campaign=mgu_ga_pre_md_pmx_hybd_mix_ca_20981607599&gad_source=1&gclid=Cj0KCQiA1p28BhCBARIsADP9HrNOQxcFEyB6yVeCY4J6cv7RxifcF1TV9rIl-E0F-9b8lYxqObQCVfgaAhfsEALw_wcB
  4. https://www.health.com/nutrition/vitamins-supplements/vitamin-d-benefits
  5. https://www.solius.com/vitamin-d-immune-system
  6. https://www.goodhousekeeping.com/health/diet-nutrition/a40983846/vitamin-d3-benefits/?utm_source=google&utm_medium=cpc&utm_campaign=mgu_ga_ghk_md_pmx_hybd_mix_ca_20310565167&gad_source=1&gclid=Cj0KCQiA1p28BhCBARIsADP9HrPb2rHShzvSp1kdb_jwK1AjQJejxr4j7eOa9aQ4rSVKGewoeJHIDncaAsImEALw_wcB
  7. https://www.naturemade.com/blogs/health-articles/what-helps-vitamin-d-absorption#:~:text=So%2C%20if%20you’re%20taking,to%20improve%20Vitamin%20D%20absorption.
  8. https://www.australianeggs.org.au/nutrition/vitamin-d#:~:text=Do%20Eggs%20Have%20Vitamin%20D,food%20sources%20of%20vitamin%20D.
  9. https://health.unl.edu/9-vitamin-d-deficiency-symptoms-and-10-high-vitamin-d-foods/

Nada Eltom

Nada Eltom (Hungary), CNP, CFMP worked as a physician (laboratory medicine specialist) in Hungary before immigrating to Canada where she earned her Certified Nutritional Practitioner, and a Certified Functional Medicine Practitioner, designations. She completed her Bachelor of Medicine and Surgery in Semmelweis University, Hungary, her Holistic Nutrition Diploma from the Institute of Holistic Nutrition, Canada and her Functional Medicine Certificate from the Functional Medicine University, USA.