Vitamin D3 - How to use the sun's energy all year round

What will you learn in this article?

Vitamin D3 is essential for the human immune system to function normally. If we are deficient, our immune system is weakened and we run the risk of getting sick more quickly. This is why colds are very common in February and March, when vitamin D stores are depleted.

Other important functions of the vitamin include maintaining bones, teeth and muscle function. In addition, vitamin D contributes to the normal absorption and utilization of calcium and regulates calcium levels in the blood!

One thing quickly becomes clear: the body cannot do without the sunshine vitamin!

1. Vitamin D formation and absorption

Vitamin D is actually not a vitamin at all, but a prohormone. This means that it is the precursor of a hormone that is only converted into an active hormone in the liver and kidneys, as well as in various cells.

This conversion always takes place in the body, regardless of whether vitamin D3 is produced with the help of sunlight or taken as a dietary supplement. Only a small part of vitamin D3, also known as cholecalciferol, is absorbed by the human body through animal products containing vitamin D.

The largest part, around 80 to 90%, is produced independently by humans in the body by converting cholesterol into vitamin D with the help of sunlight. Cholesterol is converted into vitamin D3 in the skin under the influence of UVB radiation [1,2].

2. The key function for the immune system

Research has shown that vitamin D serves as an important messenger substance for controlling the immune system. It influences both our innate and the adaptive (acquired) immune system. Every single immune cell has vitamin D receptors on its surface and is able to convert vitamin D into the active form when needed.

Vitamin D regulates the immune system so that pathogens are fought early and no physical reaction, such as a cold, occurs [3]. The human T cells, which recognize and kill pathogens, are activated by the vitamin so that pathogens are blocked.

Vitamin D supports the body's own defenses, which protect people against viruses and bacteria [4,5]. The vitamin also supports the production of defenses that protect against fungi or cancer cells, such as cathelicidin [6,7,8].

For these reasons, vitamin D deficiency should be prevented at all costs, as otherwise autoreactive T cells will form that attack the body's own cells and, in the worst case, even cause an autoimmune disease. Since vitamin D prevents the body from attacking itself because it cannot distinguish between its own and foreign cells, the vitamin is also called an immunomodulator [9,10,11].

Support for infections

The importance of an adequate supply of vitamin D has also been proven by numerous studies. An Italian study with 42 subjects showed that around 81% of COVID-19 patients suffer from a vitamin D deficiency. Patients with an acute vitamin D deficiency (below 10 ng/ml) had a 50% risk of death.

When the vitamin D level of SARS-CoV-2 infected people was above 10 ng/ml, the risk of death was only 5% and thus 10 times lower [12]. Various studies have also shown that adequate vitamin D supply has a positive effect on the course of the flu [13,14,15,16].

It is important to emphasize that vitamin D is not a cure for corona or other infectious diseases. However, a sufficient supply is a good preventative measure to protect the body.

3. Too little sun = too little vitamin D

In Germany, approximately 60% of the population is deficient in vitamin D. A D deficiency means that the body has less than 20 ng/ml of the vitamin in the blood serum [17]. This is not surprising given our geographical location and modern lifestyle.

Sunlight is needed for vitamin D to be formed in the skin. It is important to know that the wavelength of the light is of crucial importance. UV-B rays with a wavelength of 290 to 315 nm are required for D production, which varies greatly depending on the geographical location and especially the time of year. A vitamin D deficiency can therefore quickly occur, particularly in the dark season.

The ozone layer in the stratosphere fulfils its protective function by not allowing high wavelengths of light (200 to 280 nm) (UVC) and UV-B components above 290 nm to pass through. Only about 1% of UVB radiation with wavelengths above 290 nm passes through the ozone layer, meaning we only have the opportunity to absorb 1%.

The challenge: Especially in countries in the northern hemisphere, this 1% can only penetrate between 10 a.m. and 3 p.m. and only in the months of April to September. This is because only during this period is the angle between the earth and the sun short enough for the light quanta to reach a UV index of 3. Anything below a UV index of 3 is not enough to produce vitamin D [18,19]. Another challenge for D absorption is that most people are indoors at this time of day.

4. How much vitamin D does a person need?

The unit of measurement IU (International Unit) is used as the standard unit when talking about the amount of vitamin D.

It is important to know: 1 IU is equivalent to 0.025 micrograms (μg)

The German Nutrition Society does not provide an international guideline for daily requirements. In particular, in the dark months when the body cannot produce the vitamin on its own, up to 5000 IU can be taken daily. In order to find the optimal dosage for yourself, it is worth taking a blood test to determine the appropriate, individual dosage under medical supervision.

But even among doctors there are different opinions as to which value is optimal. A D level that is too low can demonstrably be detrimental to health. Now the question arises: What daily intake is healthy and sufficient?

Numerous sources define a D value between 40 and 60 ng/ml in the blood serum as ideal. Values ​​up to 60 ng/ml are considered safe in conventional, general medicine [20].

In order to benefit from the positive effects of the vitamin, experts recommend a constant, long-term intake rather than a weekly or monthly overdose. After all, our body does not produce extremely high doses all at once in sunny weather, but rather the amount needed every day to be protected.

Indigenous peoples provide the answer

Since the human organism regulates itself, an overdose caused by the body's own production of toxins in a healthy person has never been proven. For this reason, some doctors use indigenous peoples, i.e. people who still live under natural conditions, as a reference.

The aim of this study is to investigate whether an overdose of the fat-soluble vitamin D3 is possible. In these people, who live at the equator, a healthy vitamin D level of 50 to 90 ng/ml was found [21].

Liposomal Vitamin D3 + K2

A daily dose of ActiNovo's Vitamin D3+K2 corresponds to the amount of vitamin D contained in 3 liters of fortified soy milk.

5. Attention: No D3 without K2

For vitamin D to work safely and reliably, D alone is not enough. As already mentioned above, vitamin D plays a key role in controlling calcium absorption and is also responsible for the synthesis of some important proteins. In order for these proteins to become active and develop their effect, vitamin K2 is important as a co-factor.

Only in combination with K2 can the absorbed calcium be properly transported and utilized. Two of the most important human proteins, matrix GLA protein (MGP) and osteocalcin, are proven to depend on vitamin K2 [22,23,24,25].

The influence of vitamin K2

The protein osteocalcin is important for the formation of new bones. It ensures that the calcium absorbed is incorporated into the bones. Matrix GLA prevents calcium from accumulating in organs or vessels by binding the calcium and transporting it away [26]. If there is no vitamin K2 for this process, the proteins cannot work and there is a risk that the calcium will lead to calcification in the vessels and organs.

This promotes kidney stones, arteriosclerosis and numerous diseases, including heart attacks [27]. In addition, if calcium accumulates in the wrong places, it cannot fulfill its role in bone health.

The right amount of K2

If vitamin D levels are high, a vitamin K2 deficiency can quickly occur, since K2 is also used for the activation of vitamin D. In this case, vitamin K2 can no longer be used for the other processes in the body described above [28].

In this case, calcium can be deposited in the blood vessels and organs, even though the level in the blood is not too high, because vitamin K2 is missing for its utilization [29,30,31]. This is also partly the reason for the toxic effect of vitamin D in very high amounts.

Animal studies have shown that vitamin K2 deficiency can cause symptoms similar to those of a toxic, extremely high dose of vitamin D [32]. Therefore, it is not surprising that high vitamin D levels, which are normally good for bones, can increase the risk of bone fractures when vitamin K deficiency is present [33].

Remember: When taking 1000 IU of vitamin D, you should always take at least 50 micrograms of vitamin K2 at the same time.

6. The functions of K2

Vitamin K2 is involved in numerous bodily functions. The vitamin is found exclusively in animal and fermented foods. In the body, it influences the proteins osteomalacia and matrix GLA and is also involved in processes in the liver. K2 also activates the gene Gas6 (Growth Arrest Specific Gene 6), which is involved in cell division and the movement of cells in vessels and organs [34,35].

In addition to the positive effect on bones, blood vessels and skin, vitamin K2 also has anti-inflammatory properties [36]. The human brain also has an increased K2 concentration. Here, the vitamin contributes to the formation of protective compounds [37]. To explain the importance of the vitamin once again simply: If there is a vitamin K2 deficiency, there is a higher risk of dying from heart failure. This risk is just as high as in people who smoke heavily and are also susceptible to heart failure [38,39]. The latest research also shows that an adequate K2 supply should be ensured even in the case of chronic kidney disease [40].

7. The differences in the vitamin K2 form

Vitamin K has different forms, but they are very similar in their effects. The number is based on the number of chemical side arms, which range from MK4 to MK13. The most widely researched forms are MK4 and MK7.

The MK7 form accumulates most effectively in the body, ensuring a sustained and sufficient supply to all organs and tissues. The comparison: While MK7 remains available in the blood for over 72 hours (half-life), the majority of MK4 is excreted after around 1.5 hours. In addition, MK7 is significantly more effective than the MK4 form. Around 60 µg MK7 is more effective than a full 500 µg MK4 [41,42,43,44].

As with many molecules, vitamin K2 MK7 comes in two different forms: the cis and trans forms. These isomers have the same number of atoms, but a different spatial structure. Only the trans form of vitamin K2 MK7 can be used by the body. The cis form is ineffective for it! Unfortunately, many vitamin K2 products consist of up to 70 percent of the cis isomers.

A high-quality vitamin K2 dietary supplement should therefore always be labeled all-trans MK7!

8. Magnesium - an indispensable partner

What many people don’t know: A magnesium deficiency can limit the effectiveness of vitamins!

As already mentioned, vitamin D3 must first be converted by the body in order to be effective. The enzymes required for this and the transport molecules that distribute vitamin D in the body depend on magnesium. The parathyroid hormone (PTH), which is produced in the parathyroid gland and regulates D conversion, also requires magnesium.

A high intake of vitamin D can therefore also lower magnesium levels, as significantly more is used for D activation. Regardless of whether vitamin D is absorbed through the sun or in the form of a vitamin D supplement, without magnesium, vitamin D can never develop its full effect and an overdose can even be harmful [46,47,48,49,50,51].

In Germany, 26% of men and 29% of women do not consume the daily recommended DA-CH reference value for magnesium [45].

9. Study shows: Liposomal vitamin D3 + K2 has higher bioavailability

Current research shows that vitamin D3 packaged in liposomes guarantees 13x higher absorption than conventional tablets.

Since D is a fat-soluble vitamin, taking vitamin D can be a challenge. Factors such as individual human fat digestion or stomach contents can therefore lead to restrictions in vitamin D intake. The liposomal form ensures a consistent, unrestricted supply when taken daily.

The K2 used by ActiNovo is also the active MK7 all-trans form, which is present in a sufficient ratio of 75 µg all-trans MK7 K2 to 1000 IU = 25 micrograms of vitamin D3! By supplementing the mineral magnesium, the vitamin D preparation can develop its full effect.

1) Gröber U. Vitamin D3 – an old vitamin in a new light. Med Monatsschr Pharm 2010;33(10):376 – 383.

2) Sylvia Christakos, Dare V. Ajibade, Puneet Dhawan, Adam J. Fechner, Leila J. Mady, Vitamin D: Metabolism, Rheumatic Disease Clinics of North America, Volume 38, Issue 1, February 2012, Pages 1-11, ISSN 0889-857X, http://dx.doi.org/10.1016/j.rdc.2012.03. 00
3) Femke Baeke, Tatiana Takiishi, Hannelie Korf, Conny Gysemans, Chantal Mathieu, Vitamin D: modulator of the immune system, Current Opinion in Pharmacology, Volume 10, Issue 4, August 2010, Pages 482-496, ISSN 1471-489
4) Shuler FD, Hendrix J, Hodroge S, Short A (2013) Antibiotic-like actions of vitamin D. WV Med J 109:22–25 PMID: 23413544
5) Ramanathan B, Davis EG, Ross CR, Blecha F (2002) Cathelicidins: microbicidal activity, mechanisms of action, and roles in innate immunity. Microbes Infect 4:361–372 PMID: 11909747
6) Barlow PG, Svoboda P, Mackellar A, Nash AA, York IA, Pohl J, Davidson DJ, Donis RO (2011) Antiviral activity and increased host defense against influenza infection elicited by the human cathelicidin LL-37. PLoS ONE 6:e25333 PMCID: PMC3198734
7) Büchau AS, Morizane S, Trowbridge J, Schauber J, Kotol P, Bui JD, Gallo RL (2010) The host defense peptide cathelicidin is required for NK cell-mediated suppression of tumor growth. J Immunol 184:369–378 PMCID: PMC2908520
8) Bruns H, Buttner M, Fabri M, et al (2015) Vitamin D-dependent induction of cathelicidin in human macrophages results in cytotoxicity against high-grade B cell lymphoma. Science Translational Medicine 7:282ra47-282ra47 DOI:10.1126/scitranslmed.aaa3230
9) Kamen, Diane L.; TANGPRICHA, Vin. Vitamin D and molecular actions on the immune system: modulation of innate and autoimmunity. Journal of molecular medicine, 2010, Volume 88, No. 5, pp. 441-450.
10) Maria C. Borges, Lígia A. Martini, Marcelo M. Rogero, Current perspectives on vitamin D, immune system, and chronic diseases, Nutrition, Volume 27, Issue 4, April 2011, Pages 399-404, ISSN 0899-9007
11) von Essen, Marina Rode, et al. Vitamin D controls T cell antigen receptor signaling and activation of human T cells. Nature immunology, 2010, Volume 11, No. 4, pp. 344-349.
12) Carpagnano, GE; Di Lecce, V.; Quaranta, VN; Zito, A.; Buonamico, E.; Palumbo, A.; Di Gioia, G.; Valerio, VN; Resta, O. Vitamin D deficiency as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19. J. Endocrinol. Investigate 2020.
13) Zhou, J.; You, J.; Huang, L.; Wang, Y.; Shi, Y.; Lin, H. Preventive effects of vitamin D on seasonal influenza A in infants: A multicenter, randomized, open, controlled clinical trial. Pediatric Infection. Dis. J. 2018, 37, 749–754.
14) Sabetta, JR; DePetrillo, P.; Cipriani, R.J.; Smardin, J.; Burns, LA; Landry, ML Serum 25-hydroxyvitamin d and the incidence of acute viral respiratory tract infections in healthy adults. PLoS ONE 2010, 5, e11088.
15) Urashima, M.; Segawa, T.; Okazaki, M.; Kurihara, M.; Wada, Y.; Ida, H. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. On. J. Clin. Nutr. 2010, 91, 1255–1260.
16) Arihiro, S.; Nakashima, A.; Matsuoka, M.; Suto, S.; Uchiyama, K.; Kato, T.; Mitobe, J.; Komoike, N.; Itagaki, M.; Miyakawa, Y. Randomized trial of vitamin D supplementation to prevent seasonal influenza and upper respiratory infection in patients with inflammatory bowel disease. Inflamm. Bowel Dis. 2019, 25, 1088-1095.
17) https://www.dge.de/presse/pm/neue-referenzwerte-fuer-vitamin-d/
18) 1. Caldwell M, Flint S. Stratospheric ozone reduction, solar UV-B radiation and terrestrial ecosystems. Climate change. 1994; 28:375–94. doi: 10.1007/BF01104080.
19) Webb AR, Kline L, Holick MF. Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. J Clin Endocrinol Metab. 1988; 67:373–8
20) Power, M. L., & Dittus, W. P. (2017). Vitamin D status in wild toque macaques (Macaca sinica) in Sri Lanka. American Journal of Primatology, 79(6). doi:10.1002/ajp.22655
21) Uwe Gröber The most important dietary supplements - The plus for your health Südwest, 2019, ISBN: 9783641233778
22) Vermeer C, Jie KS, Knapen MH (1995) Role of vitamin K in bone metabolism. Annu Rev Nutr 15: 1-22 PMID: 8527213
23) Gallop PM, Lian JB, Hauschka PV (1980) Carboxylated calcium-binding proteins and vitamin K. N Engl J Med 302:1460–1466 PMID: 6990261
24) Hauschka PV, Lian JB, Cole DE, Gundberg CM (1989) Osteocalcin and matrix Gla protein: vitamin K-dependent proteins in bone. Physiol Rev 69:990–1047 PMID: 2664828
25) Inaba N, Sato T, Yamashita T (2015) Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trials. J Nutr Sci Vitaminol 61:471–480 PMID: 26875489
26) Haken S (2008) Vitamin K and bone health in adult humans. Vitam Horm 78:393–416 PMID: 18374202
27) Berkner KL, Runge KW (2004) The physiology of vitamin K nutrition and vitamin K-dependent protein function in atherosclerosis. Journal of Thrombosis and Haemostasis 2:2118–2132 DOI: 10.1111/j.1538-7836.2004.00968.x
28) Masterjohn C (2007) Vitamin D toxicity redefined: vitamin K and the molecular mechanism. Med Hypotheses 68:1026–1034 PMID: 17145139
29) El Asmar MS, Naoum JJ, Arbid EJ (2014) Vitamin K Dependent Proteins and the Role of Vitamin K2 in the Modulation of Vascular Calcification: A Review. Oman Med J 29:172–177 PMCID: PMC4052396
30) Theuwissen E, Smit E, Vermeer C (2012) The role of vitamin K in soft-tissue calcification. Adv Nutr 3:166–173 PMCID: PMC3648717
31) Cranenburg ECM, Vermeer C, Koos R, Boumans ML, Hackeng TM, Bouwman FG, Kwaijtaal M, Brandenburg VM, Ketteler M, Schurgers LJ (2008) The circulating inactive form of matrix Gla Protein (ucMGP) as a biomarker for cardiovascular calcification. J Vasc Res 45:427–436 PMID: 18401181
32) Luo G, Ducy P, McKee MD, Pinero GJ, Loyer E, Behringer RR, Karsenty G (1997) Spontaneous calcification of arteries and cartilage in mice lacking matrix GLA protein. Nature 386:78–81 PMID: 9052783
33) Feskanich D, Weber P, Willett WC, Rockett H, Booth SL, Colditz GA (1999) Vitamin K intake and hip fractures in women: a prospective study. Am J Clin Nutr 69:74–79 PMID: 9925126
34) Cranenburg ECM, Schurgers LJ, Vermeer C (2007) Vitamin K: the coagulation vitamin that became omnipotent. Thromb Haemost 98:120–125 PMID: 17598002
35) Vermeer C (2012) Vitamin K: the effect on health beyond coagulation – an overview. Food Nutr Res. doi: 10.3402/fnr.v56i0.5329 PMCID: PMC3321262
36) Pan MH, Maresz K, Lee PS, Wu JC, Ho CT, Popko J, Mehta DS, Stohs SJ, Badmaev V (2016) Inhibition of TNF-α, IL-1α, and IL-1β by pretreatment of human monocyte -Derived Macrophages with Menaquinone-7 and Cell Activation with TLR Agonists In Vitro. Journal of Medicinal Food 19:663–669 DOI: 10.1089/jmf.2016.0030
37) Carrié I, Portoukalian J, Vicaretti R, Rochford J, Potvin S, Ferland G (2004) Menaquinone-4 concentration is correlated with sphingolipid concentrations in rat brain. J Nutr 134:167–172 PMID: 14704312
38) Cundiff DK, Agutter PS (2016) Cardiovascular Disease Death Before Age 65 in 168 Countries Correlated Statistically with Biometrics, Socioeconomic Status, Tobacco, Gender, Exercise, Macronutrients, and Vitamin K. Cureus. doi: 10.7759/cureus.748 DOI: 10.7759/cureus.748
39) Guest GCM, de Roos NM, Sluijs I, Bots ML, Beulens JWJ, Geleijnse JM, Witteman JC, Grobbee DE, Peeters PHM, van der Schouw YT (2009) A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis 19:504–510 PMID: 19179058
40) Westenfeld R, Krueger T, Schlieper G, et al (2012) Effect of vitamin K2 supplementation on functional vitamin K deficiency in hemodialysis patients: a randomized trial. Am J Kidney Dis 59:186–195 PMID: 22169620
41) Schurgers LJ, Teunissen KJF, Hamulyak K, Knapen MHJ, Vik H, Vermeer C (2007) Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood 109:3279–3283 DOI: 10.1182/blood-2006-08-040709
42) Schurgers LJ, Knapen MHJ, Vermeer C (2007) Vitamin K2 improves bone strength in postmenopausal women. International Congress Series 1297:179-187 DOI: 10.1016/j.ics.2006.08.006
43) Sato T, Schurgers LJ, Uenishi K (2012) Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J 11:93 PMCID: PMC3502319
44) Schurgers LJ, BV VPV, Thomas CP (2008) Vitamin K2 as MenaQ7™.
45) www.mri.bund.de/fileadmin/MRI/Institute/EV/NVSII_Final Report_Part_2.pdf, p. 141
46) Zofková I, Kancheva RL. The relationship between magnesium and calciotropic hormones. Magnesium Research: Official Organ of the International Society for the Development of Research on Magnesium [1995, 8(1):77-84]
47) Risco F, Traba ML. Influence of magnesium on the in vitro synthesis of 24,25-dihydroxyvitamin D3 and 1 alpha, 25-dihydroxyvitamin D3. Magnes Res. 1992;5:5–14.
48) Risco F, Traba ML. Possible involvement of a magnesium dependent mitochondrial alkaline phosphatase in the regulation of the 25-hydroxyvitamin D3-1 alpha-and 25-hydroxyvitamin D3-24R-hydroxylases in LLC-PK1 cells. Magnes Res. 1994;7:169–178.
49) Rösler A, Rabinowitz D. Magnesium-induced reversal of vitamin-D resistance in hypoparathyroidism. Lancet. 1973 Apr 14;1(7807):803-4.
50) Zittermann, Armin. Magnesium deficiency? overlooked cause of low vitamin D status?. BMC medicine, 2013, 11th year, No. 1, p. 229.
51) Rude RK, Adams JS, Ryzen E, Endres DB, Niimi H, Horst RL, Haddad JG Jr, Singer FR. Low serum concentrations of 1,25-dihydroxyvitamin D in human magnesium deficiency. J Clin Endocrinol Metab. 1985;61:933-940.