top of page
vitamin d blood.jpg

Vitamin D may help prevent blood clots and Covid-19


The anti-thrombotic property of vitamin D has been substantiated by several clinical studies that found vitamin D deficiency was associated with blood clots. Low levels of 25(OH)D were found to be associated with deep vein thrombosis (DVT) [1] and low levels of vitamin D were also predictive of DVT in patients with ischemic stroke [2].


Sensible sun exposure is the most effective method of increasing vitamin D levels and may help reduce the risk of blood clots.
An 11year study of 30,000 women found those who had greater sun exposure had a 30% lower risk of Venous thromboembolism[VTE] and the authors stated the extra sun exposure must have improved the vitamin D status which was manifested in the reduced risk of VTE[3]


Sun and Covid-19 prevention

Ultraviolet A Radiation from the Sun found to reduce COVID‐19 Deaths in the USA with replication studies in England and Italy
More evidence of the benefits of sun exposure.
Researchers from the University of Edinburgh compared all recorded deaths from Covid-19 in the continental US from January to April 2020 with UV levels for 2,474 US counties for the same time period.
The study found that people living in areas with the highest level of exposure to UVA rays which makes up 95 per cent of the sun's UV light had a lower risk of dying from Covid-19 compared with those with lower levels. The analysis was repeated in England and Italy with the same results.


Study confirms that vitamin D is beneficial in the fight against COVID-19
Vitamin D supplements given to COVID 19 patients with low vitamin D reduced the risk of being mechanically ventilated and passing away at just 1000iu weekly.

Those in this study were in hospital out of the sun and with low vitamin D. Supplementing with 1000iu one per week, although helpful as this study found, is usually not enough to raise blood vitamin D levels to over 50 nmol/lt and at best, around 75nmol/lt which other studies have found to be beneficial.
As the authors of the study state “it is clear that patients with low vitamin D should receive supplementation not only for bone health, but also for stronger protection against severe COVID-19
Isn’t it about time health authorities in Australia mandated correcting vitamin D levels in hospital and institutionalised patients along with the positive confirmation and need for vaccination?(5)

Higher levels of Vitamin D may lower risk of Covid-19 infections
A study at the University of Chicago Medicine found having vitamin D levels above those traditionally considered sufficient may lower the risk of COVID-19 infection, especially for Black people.
Black individuals who had levels of 75 to 100 nmol/l had a 2.64 times higher risk of testing positive for COVID-19 than people with levels of 100 ng/ml or greater.(6)

Vitamin D supplementation should be a standardised practice to treat COVID-19 in hospitalised older patients,

According to a newly published position statement by the Spanish Society of Geriatrics and Gerontology. The paper notes a meta-analysis​ which described a lower mortality rate in patients in whom vitamin D was administered (10.6%) compared to controls (23.9%). The vitamin doses administered were heterogeneous across studies ranging from a single dose of 400,000 IU of cholecalciferol the day of hospital admission, to 50,000 IU in patients who did not receive more than 800 IU per day during the month prior to the hospital admission.
Studies have also hypothesised the possible beneficial effect of vitamin D supplementation in patients with COVID-19 stems from restoration of immune balance which then prevents the hyperinflammatory cytokine storm since immune dysregulation is a key feature of severe COVID-19. (7)

It could be advantageous to examine vitamin D Statius in people at risk of blood clots and COVID. Further studies are urgently needed.

Importantly if you suspect you have a blood clot or feel you are at risk or have any symptoms of COVID-19 always see your healthcare professional

1. Khademvatani K (2014) Int J Gen Med 7:303–309. &. Dehghani K (2019) Biomed. Res. Ther.6:3107–3112
2. Wu WX (2018) Clin Appl Thromb Hemost 24(9 suppl):69S-75S
3. Lindqvist PG (2009) Thromb Haemost 7(4):605–610.

4. M. Cherrie et al, British Journal of Dermatology 08 April 2021

5. The Endocrine Society. "Supplements may protect those with low vitamin D levels from severe COVID-19: Study finds more than half of patients with low vitamin D do not receive supplements." ScienceDaily. ScienceDaily, 21 March 2021.

6. Association of Vitamin D Levels, Race/Ethnicity, and Clinical Characteristics With COVID-19 Test Results. JAMA Network Open, 2021

7. Francisco J. et al VitaminD supplementation for the prevention and treatment of COVID-19: a position statement from the Spanish Society of Geriatrics and Gerontology January 2021

bottom of page