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Article: Should I Take Vitamin D?

Should I Take Vitamin D?

Should I Take Vitamin D?


It seems that ever since the start of the pandemic that the talk of Vitamin D in America has been everywhere, with a large focus on how it plays a role in “boosting immunity.” You may have also heard that it can play a role in elevating your mood and energy levels. These claims about Vitamin D are backed-up with high quality research studies. Therefore, it is important to be aware of the signs of deficiency and know how to supplement your body with Vitamin D.

What is Vitamin D?

It turns out that Vitamin D is actually not a vitamin at all, but a hormone. Our bodies cannot make Vitamin D, so we must get it from outside sources. Vitamin D helps our body absorb both calcium and phosphorus, which helps maintain strong bones. If someone is deficient in Vitamin D, then their body is also unable to absorb calcium and phosphorus well. Natural sunlight is the best way for our bodies to get Vitamin D. When sunlight touches our skin, the ultraviolet radiation is converted into Vitamin D in our bodies. This can be difficult for those of us that are sensitive to UV exposure or live in areas that don’t receive much sunlight, especially during the winter months. Most humans can get enough Vitamin D by only spending 10-30 minutes everyday outside in the sun. You can also obtain Vitamin D from your diet as well, from foods like eggs, salmon, canned tuna, certain mushrooms, and dairy products. This hormone has been shown to have many beneficial effects in our bodies including: bone health, mood regulation, immunity benefits, improved energy levels, and hormone regulation.

Signs of Deficiency 

  • Fatigue
  • Weakened bones or bone pain
  • Muscle weakness
  • Low mood, anxious feelings
  • Muscle cramps
  • Lowered immunity, getting sick more often
  • Impaired wound healing
  • Hair loss

If you suspect that you may have a Vitamin D deficiency, you should ask your primary care provider to get your blood drawn for labs. In the long term, low Vitamin D levels have also been associated with osteoporosis, rickets, and bone fractures. For reference the adequate Vitamin D levels are above 30 ng/mL.  Some causes of Vitamin D deficiency include: limited sun exposure, darker skin pigments, malnutrition, cancer, kidney/liver failure, and certain pharmaceutical medications.

Importance of Vitamin D

One of the first signs of Vitamin D deficiency that appears is fatigue. This symptom has been linked to lack of Vitamin D in numerous controlled scientific research trials. A 2016 double-blind placebo controlled trial investigated how a single oral dose of 100,000 units of Vitamin D worked to improve chronic fatigue presentation in participants with low Vitamin D serum levels when compared to placebo. The fatigue levels reported by the participants that received Vitamin D significantly decreased, and complete amelioration of fatigue was also reported more frequently in the Vitamin D group. Low Vitamin D levels have also often been linked to low mood and feelings of sadness, which is why people often cite getting outdoors and getting some sunshine as a cure to feeling down.

A 2022 took the Vitamin D levels of both healthy participants and those experiencing depression, and found that a higher frequency of the individuals with depression had Vitamin D deficiency. This study provides further evidence in the importance of obtaining natural Vitamin D or supplementation in the treatment of low mood. The connection between Vitamin D and immunity became a popular discussion during the start of the COVID-19 pandemic. Since 2020, several studies have analyzed how Vitamin D levels can affect our immune system and decreased mortality from viruses like COVID-19 in hospitalized patients. One such study was a meta-analysis completed in 2021. The study investigated whether Vitamin D status was associated with COVID-19 severity, defined as acute respiratory distress requiring admission to the ICU or mortality. Findings were that Vitamin D severe deficiency was associated with both ICU admission and mortality among COVID-19 patients. These findings mirror those of similar studies. Vitamin D supplement can be an important tool for those who are starting to feel a cold/virus coming on, as well as for those that are currently experiencing symptoms.

Correct Supplementation

There are two types of Vitamin D that you’ll find in supplements: Vitamin D2 (ergocalciferol) and D3 (cholecalciferol). Vitamin D2 is derived from plants and Vitamin D3 comes from an animal source. Studies have shown that Vitamin D3 is better absorbed by the human body than D2 and is more effective at raising blood serum Vitamin D levels.

Vitamin D is fat-soluble, and therefore should be taken after or with a meal. The amount of Vitamin D that you’ll take depends on whether you are deficient or not as well as characteristics such as age, race, and season. You should come up with a plan with your doctor to determine the appropriate dose for you, but most providers and guidelines recommend a daily supplementation of 400-800 IU. If you are deficient, it may be recommended that you supplement with 5,000 IU Vitamin D.

Vitamin D & Magnesium

It is recommended that someone who is deficient in Vitamin D also take a calcium and magnesium supplement. If you have low levels of magnesium, then your body is not able to fully absorb the Vitamin D supplements you are taking. Magnesium helps your body convert the supplement to an active form of Vitamin D that can be aboard by your body and increase your blood serum levels. Taking such high doses of Vitamin D supplements can also consequently lower magnesium levels, so it is important to supplement with both at the same time.

Guidelines currently recommend taking 310-320 mg of magnesium glycinate supplement per day for women and 400-420 mg per day for men. You can also increase your magnesium levels by adding more fiber to your diet.

In conclusion

Vitamin D plays an important role in your health and if you are experiencing any of the symptoms of deficiency you should contact your provider to get your labs checked and work with them to come up with a plan to optimize your health with supplementation.


  1. 9 Vitamin D deficiency symptoms (and 10 high Vitamin D Foods). University of Nebraska-Lincoln. 
  2. Nowak A, Boesch L, Andres E, Battegay E, Hornemann T, Schmid C, Bischoff-Ferrari HA, Suter PM, Krayenbuehl PA. Effect of Vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial. Medicine (Baltimore). 2016 Dec;95(52):e5353. doi: 10.1097/MD.0000000000005353. Erratum in: Medicine (Baltimore). 2017 Jan 20;96(3):e6038. PMID: 28033244; PMCID: PMC5207540.
  3. Khan, B., Shafiq, H., Abbas, S. et al. Vitamin D status and its correlation to depression. Ann Gen Psychiatry. 2022;21,32.
  4. Chiodini I, Gatti D, Soranna D, Merlotti D, Mingiano C, Fassio A, Adami G, Falchetti A, Eller-Vainicher C, Rossini M, Persani L, Zambon A, Gennari L. Vitamin D Status and SARS-CoV-2 Infection and COVID-19 Clinical Outcomes. Front Public Health. 2021 Dec 22;9:736665. doi: 10.3389/fpubh.2021.736665. PMID: 35004568; PMCID: PMC8727532.

This article was edited by Dr. Swathi and was written by Element Apothec Scientific Communications Intern, Melanie Flores. She is a Doctor of Pharmacy (PharmD) student at Oregon State University and Oregon Health & Science University College of Pharmacy in Portland, Oregon.

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