Close this search box.

How to Prevent Vitamin D Deficiency?

Share on:
How to Prevent Vitamin D Deficiency?

Vitamin D plays a crucial role in many bodily functions, and insufficient levels can lead to various health problems. It is essential to develop strategies to help the general population achieve sufficient levels of Vitamin D, and ideally, reach optimal levels for better health.

A recommended strategy to prevent and target vitamin D deficiency and guarantee sufficient levels should encompass three complementary approaches1,2,3.

  1. Gradual and sensible sun exposure
  2. Dietary intake of foods rich or fortified with vitamin D
  3. Supplementation with Vitamin D

How to Raise Vitamin D

1. Gradual and Sensible Sun Exposure

  • A lack of exposure to sunlight may lead to a deficiency of vitamin D.
  • Start gradually, first exposing your skin to the sun for a small amount of time. Then gradually increase sun exposure.
  • This is crucial if you’ve been avoiding the sun, often covered outdoors, or live in places with harsh winters and little sunlight during certain seasons.
  • Do not expose the skin to the point of erythema (reddening) or sunburn.
  • Erythema is the primary cause of both melanoma and non-melanoma skin cancer.
  • The minimum amount of time in the sun should be around 10-15 minutes and then progressing to longer durations1,3.
  • The appropriate duration of exposure is highly dependent on several factors such as level of skin pigmentation, age, and prior sun exposure.
  • Try to have your body as exposed as possible, with fully naked being ideal! We know that is hard, so try at least to have the arms and legs or the hands, arms, and face exposed to the sun1,3.
  • Aim for at least two to four days of sun exposure a week1,3.
  • The best time to get the most vitamin D production is between 10 am and 3 pm when the sun is at its peak. The time at which the sun is at its peak varies according to your geographical location.
  • Older people and those with darker skin will need longer periods of sun exposure.

As an example, an article published in 2023 indicated that in the summer (in Poland, where the study was conducted), to produce enough vitamin D through sun exposure, people should aim at4:

  • exposing 18% of the body to the sun without sunscreen.
  • approximately 15–30 minutes a day for fair-skinned children aged 4–10 years.
  • approximately 30–45 minutes a day for adolescents, adults, and seniors.
  • sun exposure should be between 10 a.m. and 3 p.m

This gradual and careful exposure aims to reduce the risk of sunburn and sun-related skin issues, such as melanoma and non-melanoma skin cancer, while maximizing the production of Vitamin D. The area of the skin exposed is of foremost importance to achieve optimal skin synthesis of vitamin D. Try to expose as much  of your skin as possible when sunbathing. The duration will vary with the level of skin pigmentation (melanin present in the skin) and age, being inversely proportional. This means older people and those with darker skin will need longer periods of sun exposure. The duration of exposure is important, but more time in the sun does not mean more vitamin D. Spend the right amount of time in the sun for optimal vitamin D production. During the initial exposure to sunlight, provitamin D3 is efficiently converted to previtamin D3, but with continued exposure, no more than 10-20% of the initial provitamin D3 will end up as previtamin D35. Interestingly, sunlight itself regulates the production of vitamin D3 in the skin, and too much exposure to sunlight will cause its breakdown (known as photodegradation)2. Hence, when it comes to sunlight, more is not always better.

2. Dietary intake of foods rich or fortified with vitamin D

  • Increase intake of vitamin D-rich or enriched foods.
  • Very few foods naturally contain vitamin D. For non-vegans, these include wild-caught oily fish like salmon, mackerel, sardines, liver, and egg yolk. Vegan options comprise UV-exposed mushrooms, broccoli, green onion, parsley, and watercress.
  • A study reviewing the literature on sources of vitamin D highlighted exactly this – not many foods are a rich source of vitamin D (considering levels above 4 μg/ 100g)6.
  • Vegan sources: Best are mushrooms (21.1-58.7 μg/ 100g) and Reindeer lichen (87 μg/ 100g). In small amounts dark chocolate (4 μg/ 100g)6.
  • Animal sources: Many but not all fish* (5-25 μg/ 100g) and fish liver oils (250 μg/ 100g). In small amounts cheese, beef liver, and eggs (1.3-2.9 μg/ 100g) 6.
  • Fortified foods can be another source of dietary vitamin D and you can find it in several products, such as certain grains and plant-based milks.
  • Fortified foods can contain D3 or D2 forms or 25-hydroxy vitamin D (a vitamin D metabolite that can be obtained through diet)6.
  • Vitamin D2 or D3, both obtained through diet or endogenously produced, are stored in fat cells and released to circulation upon demand1.

3. Supplementation with Vitamin D

  • Vitamin D supplementation can be a reasonable approach to guarantee vitamin D sufficiency and to rapidly correct deficiency.
  • There is some controversy regarding vitamin D3 versus vitamin D2 for achieving and maintaining higher serum 25(OH)D (calcidiol) levels.
  • Although some researchers consider that both vitamin D2 and vitamin D3 can be used for vitamin D supplementation with similar results7,8,9, a recent meta-analysis indicates that vitamin D3 is more efficacious at raising serum 25(OH)D concentrations than vitamin D210. In this article from 2012, an electronic search was conducted, using data from January 1966 to July 2011, of all relevant adult studies that directly compare vitamin D3 with vitamin D2. The conclusion was that vitamin D3 could potentially become the preferred choice for supplementation. The authors refer, however, that “additional research is required to examine the metabolic pathways involved in oral and intramuscular administration of vitamin D and the effects across age, sex, and ethnicity10.
  • A 12-week randomized, placebo-controlled food-fortification trial using daily supplementation with 15 μg of vitamin D2 compared with vitamin D3 also showed that vitamin D3 was more effective than vitamin D2 in increasing serum 25(OH)D in the wintertime11. An 8-week randomized-controlled trial in Finland reached similar results, supporting the evidence that D2 is less potent than D3 in increasing total serum 25(OH)D concentrations12.

Vitamin D Screening

Early detection and action can help prevent the global vitamin D deficiency pandemic and sufficient vitamin D levels may also reduce the risk of developing many of the health issues and chronic conditions that have been associated with vitamin D deficiency1,3.

While some experts argue against routine screening for healthy children and adults13, others believe yearly and regular monitoring can identify and prevent deficiency1. For most people, getting more vitamin D through diet, supplementation, and sensible sun exposure can help avoid deficiencies14.

Screening is especially important for people with deeply pigmented skin, those who wear clothing that covers most of the body, during pregnancy, and for the elderly, or people in institutions. Supplementation might be an important strategy to prevent and reverse vitamin D deficiency in these populations13.

People with certain conditions, such as genetic or acquired photosensitivity disorders that may require strict photoprotection, a history of skin cancer, organ transplant recipients, and those with malabsorption syndromes are also at higher risk of vitamin D deficiency. It’s strongly recommended that these groups undergo screening and supplementation3,13.

A D-lightful vitamin

Boosting vitamin D levels in young and middle-aged adults can lower the risk of autoimmune diseases, deadly cancers (such as prostate, colon, and breast cancer), type II diabetes, heart disease, cognitive issues, and infectious diseases. In children, maintaining sufficient vitamin D levels helps lower the risk of asthma, wheezing disorders, and upper respiratory tract infections, including influenza. It will also reduce their risk of developing, in the future, chronic conditions associated with insufficient vitamin D levels3.

In one sentence, calcitriol, the active form of Vitamin D, can be considered the body’s most “powerful hormone”!

1. Wacker M, Holick MF. Sunlight and Vitamin D: A global perspective for health. Dermatoendocrinol. 2013 Jan 1;5(1):51-108. doi: 10.4161/derm.24494. PMID: 24494042; PMCID: PMC3897598.

2. Webb AR, DeCosta BR, Holick MF. Sunlight regulates the cutaneous production of vitamin D3 by causing its photodegradation. J Clin Endocrinol Metab 1989; 68:882 – 7;; PMID: 2541158

3. Holick MF. Vitamin D: a d-lightful solution for health. J Investig Med. 2011;59(6):872-880. doi:10.2310/JIM.0b013e318214ea2d

4. Płudowski P, Kos-Kudła B, Walczak M, Fal A, Zozulińska-Ziółkiewicz D, Sieroszewski P, Peregud-Pogorzelski J, Lauterbach R, Targowski T, Lewiński A, Spaczyński R, Wielgoś M, Pinkas J, Jackowska T, Helwich E, Mazur A,

Ruchała M, Zygmunt A, Szalecki M, Bossowski A, Czech-Kowalska J, Wójcik M, Pyrżak B, Żmijewski MA, Abramowicz P, Konstantynowicz J, Marcinowska-Suchowierska E, Bleizgys A, Karras SN, Grant WB, Carlberg C, Pilz S, Holick MF, Misiorowski W. Guidelines for Preventing and Treating Vitamin D Deficiency: A 2023 Update in Poland. Nutrients. 2023 Jan 30;15(3):695. doi: 10.3390/nu15030695. PMID: 36771403; PMCID: PMC9920487.

5. Holick MF. Photosynthesis of vitamin D in the skin: effect of environmental and life-style variables. Fed Proc. 1987 Apr;46(5):1876-82. PMID: 3030826.

6. Benedik E. Sources of vitamin D for humans. Int J Vitam Nutr Res. 2022 Mar;92(2):118-125. doi: 10.1024/0300-9831/a000733. Epub 2021 Oct 18. PMID: 34658250.

7. Biancuzzo RM, Clarke N, Reitz RE, Travison TG, Holick MF. Serum concentrations of 1,25-dihydroxyvitamin D2 and 1,25-dihydroxyvitamin D3 in response to vitamin D2 and vitamin D3 supplementation. J Clin Endocrinol Metab. 2013;98(3):973–979.

8. Fisk CM, Theobald HE, Sanders TA. Fortified malted milk drinks containing low-dose ergocalciferol and cholecalciferol do not differ in their capacity to raise serum 25-hydroxyvitamin D concentrations in healthy men and women not exposed to UV-B. J Nutr. 2012 Jul;142(7):1286-90. doi: 10.3945/jn.111.156166. Epub 2012 May 23. PMID: 22623396.

9. Holick MF, Biancuzzo RM, Chen TC, et al. Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D. J Clin Endocrinol Metab. 2008;93(3):677–681.

10. Tripkovic L, Lambert H, Hart K, Smith CP, Bucca G, Penson S, Chope G, Hyppönen E, Berry J, Vieth R, Lanham-New S. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. Am J Clin Nutr. 2012 Jun;95(6):1357-64. doi: 10.3945/ajcn.111.031070. Epub 2012 May 2. PMID: 22552031; PMCID: PMC3349454.

11. Tripkovic L, Wilson LR, Hart K, Johnsen S, de Lusignan S, Smith CP, Bucca G, Penson S, Chope G, Elliott R, Hyppönen E, Berry JL, Lanham-New SA. Daily supplementation with 15 μg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial. Am J Clin Nutr. 2017 Aug;106(2):481-490. doi: 10.3945/ajcn.116.138693. Epub 2017 Jul 5. PMID: 28679555.

12. Itkonen ST, Skaffari E, Saaristo P, Saarnio EM, Erkkola M, Jakobsen J, Cashman KD, Lamberg-Allardt C. Effects of vitamin D2-fortified bread v. supplementation with vitamin D2 or D3 on serum 25-hydroxyvitamin D metabolites: an 8-week randomised-controlled trial in young adult Finnish women. Br J Nutr. 2016 Apr 14;115(7):1232-9. doi: 10.1017/S0007114516000192. Epub 2016 Feb 11. PMID: 26864127.

13. Passeron T, Bouillon R, Callender V, Cestari T, Diepgen TL, Green AC, van der Pols JC, Bernard BA, Ly F, Bernerd F, Marrot L, Nielsen M, Verschoore M, Jablonski NG, Young AR. Sunscreen photoprotection and vitamin D status. Br J Dermatol. 2019 Nov;181(5):916-931. doi: 10.1111/bjd.17992. Epub 2019 Jul 15. PMID: 31069788; PMCID: PMC6899926.

14. Holick MF. High prevalence of vitamin D inadequacy and implications for health. Mayo Clin Proc. 2006 Mar;81(3):353-73. doi: 10.4065/81.3.353. PMID: 16529140.

Recent Posts