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Where does supplementary Vitamin D3 come from?

Vitamin D, often called the "sunshine vitamin," is an essential nutrient for our overall health and well-being. It plays a crucial role in bone health, immune function, and even mental health. While our bodies can synthesize vitamin D when exposed to sunlight, many individuals worldwide struggle to maintain optimal levels. As a result, vitamin D3 supplements have gained popularity.

In this blog post, we'll delve into the fascinating process of how vitamin D3 is made for supplements.

Sourcing Raw Materials for vitamin D3:

The journey of vitamin D3 supplements begins with sourcing the raw materials. The primary source of vitamin D3 is lanolin, a natural oil found in sheep's wool. Lanolin is chosen as a starting material due to its high concentration of 7-dehydrocholesterol, a precursor to vitamin D3.

Extraction and Purification:

Once obtained, the lanolin undergoes a rigorous extraction and purification process. The lanolin is first washed and treated to remove impurities and contaminants. Next, it is exposed to ultraviolet (UV) light, which triggers a chemical reaction that converts 7-dehydrocholesterol into pre-vitamin D3.


The pre-vitamin D3 obtained from the lanolin is not yet biologically active. It needs to be further processed to convert it into its active form, vitamin D3. To achieve this, the pre-vitamin D3 undergoes a process known as thermal isomerization. It is heated to a specific temperature, which causes a rearrangement of its molecular structure, resulting in the formation of vitamin D3.

Stabilization and Formulation:

After the activation process, the vitamin D3 is stabilized to prevent degradation. It is typically mixed with a carrier oil, such as olive oil or coconut oil, to enhance absorption and ensure even distribution within the supplement. Other ingredients, such as antioxidants, may also be added to prolong the shelf life of the supplement.

Quality Control and Testing:

To ensure the safety, potency, and purity of the vitamin D3 supplement, rigorous quality control measures are implemented. Samples are tested for microbial contamination, heavy metals, and other impurities. Additionally, the concentration of vitamin D3 is verified to ensure it meets the labelled dosage.

Packaging and Distribution:

Once the quality control tests have been successfully passed, the finished vitamin D3 supplements are packaged for distribution. They may be available in various forms, such as capsules, tablets, liquid drops or in powder mixes, catering to different preferences and requirements.

Synthetic vitamin D3:

There is also an artificial form of vitamin D3 available. It is known as synthetic vitamin D3 or cholecalciferol. Synthetic vitamin D3 is produced through chemical processes in a laboratory, typically from plant sterols or ergosterol (a sterol found in fungi). While the molecular structure of synthetic vitamin D3 is near identical to the vitamin D3 produced in the body or obtained from natural sources, some individuals may have concerns about the origin or manufacturing process of synthetic vitamins.

Metulas Supplements always sources vitamins from natural sources and considers these to provide a higher rate of absorption. Vitamin D3 from lanolin is suitable for vegetarians as it is a by-product of the wool industry and no sheep are harmed during the process!

When choosing a vitamin D3 supplement, it is crucial to ensure that the product meets quality and safety standards. Look for reputable brands that undergo rigorous testing and adhere to Good Manufacturing Practices (GMP). These supplements should clearly indicate whether the vitamin D3 is derived from natural sources or is synthetic. Metulas Supplements is a name that can be trusted and all its products are manufactured in the UK in GMP certified facilities.

It is of course worth remembering that obtaining vitamin D through natural sources, such as sunlight exposure or consuming vitamin D-rich foods like fatty fish and fortified dairy products, is a great way to add to any supplementation being taken. Sunlight triggers the production of vitamin D3 in the skin, and natural food sources provide a range of other essential nutrients. However, in cases where sunlight exposure is limited or dietary sources are insufficient, vitamin D3 supplements can be a valuable tool in maintaining optimal vitamin D levels.

As always remember that while supplements can be beneficial for those with low vitamin D levels, they should not replace a healthy lifestyle and regular exposure to sunlight, which remains a great natural way to maintain adequate vitamin D levels, depending on the sun shinning of course!

Always consult with a healthcare professional for personalized advice regarding vitamin D supplementation.

Metulas Supplements is a British brand committed to delivering top-quality amino acid-based Food Supplement Drink Mixes. A family-owned business that prides itself on its dedication to scientific research and product quality. Every formulation offered has been created by a team of expert nutritionists and scientists and every line of production undergoes rigorous test and quality control procedures, ensuring every tub meets the highest standards of efficacy and safety; and most importantly the formulations do what they say they are going to do! All Metulas Supplements Food Supplement Drink Mixes are made in the UK - a country recognised for its world class manufacturing. The team are committed to customer satisfaction and customer support. If you have any questions relating to any information in these blogs or would like to know more about the products of Metulas Supplements or have any questions at all - head over to and drop us a line!



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