How to take vitamin D3
Vitamin D is more than a vitamin, it is a hormone that fulfils essential functions in our bodies. This means we need to ingest it through our diets or as a supplement, since our body cannot synthesize it by itself.
Vitamin D is formed from cholesterol when our bodies are exposed to sunlight. But many of us fail to maintain adequate levels of vitamin D in our bodies (1).
Vitamin D3 is found in what foods
The most common dietary sources of vitamin D are oily fish (from phytoplankton) and egg yolks. These foods contain a type of vitamin D called cholecalciferol, known as vitamin D3.
Vitamin D2, or ergocalciferol, is found in plant-based sources such as plants, fungi and yeasts, which are also formed from a precursor compound (provitamin D2) and sunlight exposure. However, a study conducted in 2001 found that a species of lichen (Cladina Spp) also contains vitamin D3 in greater or lesser concentrations depending on sunlight exposure. This indicates that vitamin D3 is also found in the plant kingdom (2). Fortified foods such as dairy and cereals are another source of vitamin D (3).
Both ergocalciferol (Vitamin D2) and cholecalciferol (Vitamin D3) need to be activated to perform their functions. First, they are converted in the liver into the compound calcidiol or 25(OH) D. This compound is then transformed in the kidneys into 1.25 (OH) 2D, the active form of vitamin D known as calcitriol which acts as a hormone in our bodies.
Vitamin D3 benefits
The main properties of vitamin D3 include three highly important benefits:
Supports bone health
One of the most well-known functions of vitamin D is its ability to regulate the absorption of calcium in the intestines. This makes it an essential vitamin for maintaining bone health. It even supports the maintenance of calcium and phosphorus levels in the blood, combined with the action of the hormones parathormone and calcitonin.
Helps to maintain a healthy immune system
Vitamin D receptors and activating enzymes are found on the surface of white blood cells. The role of vitamin D in regulating the immune system is complex and vital for balancing immunity. Over-stimulation and immunosuppression of the immune system can both be linked to vitamin D levels.
A study of Canadian children and adolescents found that low levels of vitamin D in the blood were associated with frequent upper respiratory tract infections (4). In another study, the protective role of vitamin D against influenza was demonstrated as being linearly associated with a lower rate of seasonal respiratory infections, together with improved lung function (5).
Promotes healthy muscle function
Vitamin D regulates neuromuscular functioning (related to the nervous and muscular systems) and impacts protein synthesis. Studies suggest that people with vitamin D seric levels below 30 nmol/l have reduced muscle strength, weakness and wasting. In addition, those with vitamin D receptor polymorphisms (a genetic variation) experience muscle dysfunction (6).
When to take Vitamin D3?
Many factors can contribute to a low concentration of vitamin D. The most common is lack of sunlight. Vitamin D deficiency symptoms are not always obvious, and many people go years without proper diagnosis and treatment.
The most common symptoms of lack of vitamin D are:
- General tiredness and fatigue
- Muscle pain
- Frequent respiratory infections
- Bone pain and even fractures
- Impaired wound healing
- Hair loss
Your doctor may recommend a blood test to check vitamin D concentration, in addition to the clinical test. Supplementation is then likely to be recommended.
Current vitamin D requirements are (7):
- children and adolescents: 600 IU
- adults up to 70 years of age: 600 IU
- adults over 70: 800 IU
- pregnant or breastfeeding women: 600 IU
To improve absorption, taking a vitamin D supplement with a meal is recommended. Foods rich in fats, such as avocados, nuts and seeds, are particularly useful for increasing absorption of vitamin D into the bloodstream. Foods rich in calcium and proteins are also a good way to enhance the bioavailability of vitamin D.
According to one study, people who took vitamin D supplements together with a meal rich in fats had 32% higher levels of vitamin D in their blood after 12 hours, compared with people who ate a fat-free meal. This is because vitamin D is a fat-soluble vitamin (8).
Vitamin D3 supplements
Vitamin D3 supplements are commonly recommended for people with low sunlight exposure, who live in countries with long winter seasons or who work indoors for much of their day.
Anastore’s Vitamin D3 is one of the best quality supplements on the market. This product offers numerous advantages over similar products:
- It is a 100% vegan supplement approved by the Vegan Society and the Vegetarian Society, and its main source of vitamin D3 is Cladina Spp. lichen. This lichen is a symbiosis between an algae and a fungus, and has high bioavailability, especially when ingested together with a dietary source of fat.
- It has no smell or taste, unlike many cod liver oil or other oily fish-based supplements.
- It contains no artificial additives or dyestuffs.
- It is approved by regulatory bodies.
Adding a vegan Vitamin D3 supplement can help you avoid many problems that are commonly misdiagnosed (chronic fatigue, muscle pain, recurring infections).
- Grant WB, Holick MF. Benefits and requirements of vitamin D for optimal health: a review. Altern Med Rev. 2005;10(2):94‐111.
- Wang T, Bengtsson G, Kärnefelt I, Björn LO. Provitamins and vitamins D₂and D₃in Cladina spp. over a latitudinal gradient: possible correlation with UV levels [published correction appears in J Photochem Photobiol B 2001 Dec;65(1):85]. J Photochem Photobiol B. 2001;62(1-2):118‐122. doi:10.1016/s1011-1344(01)00160-9.
- Calvo MS, Whiting SJ, Barton CN. Vitamin D fortification in the United States and Canada: current status and data needs. Am J Clin Nutr. 2004;80(6 Suppl):1710S‐6S. doi:10.1093/ajcn/80.6.1710S.
- Science M, Maguire JL, Russell ML, Smieja M, Walter SD, Loeb M. Low serum 25-hydroxyvitamin D level and risk of upper respiratory tract infection in children and adolescents. Clin Infect Dis. 2013;57(3):392‐397. doi:10.1093/cid/cit289.
- Berry DJ, Hesketh K, Power C, Hyppönen E. Vitamin D status has a linear association with seasonal infections and lung function in British adults. Br J Nutr. 2011;106(9):1433‐1440. doi:10.1017/S0007114511001991.
- Tanner SB, Harwell SA. More than healthy bones: a review of vitamin D in muscle health. Ther Adv Musculoskelet Dis. 2015;7(4):152‐159. doi:10.1177/1759720X15588521.
- Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Ross AC, Taylor CL, Yaktine AL, et al., editors. Dietary Reference Intakes for Calcium and Vitamin D. Washington (DC): National Academies Press (US); 2011.
- Dawson-Hughes B, Harris SS, Lichtenstein AH, Dolnikowski G, Palermo NJ, Rasmussen H. Dietary fat increases vitamin D-3 absorption. J Acad Nutr Diet. 2015;115(2):225‐230. doi:10.1016/ j.jand.2014.09.014.