Vitamin D

What exactly is vitamin D and what is it good for?

You may be surprised to learn that vitamin D isn't just a fat-soluble vitamin – it actually functions as a steroid hormone, whose active form influences the expression of hundreds of genes and without which the body cannot fully utilise calcium from food. Research shows that calcium absorption increases significantly with rising 25(OH)D levels (Heaney et al., 2003).

Why does this matter? Because vitamin D deficiency develops slowly and imperceptibly: fatigue, slower recovery, and a weakened immune system.

What is vitamin D for?

What are the effects of vitamin D? Demonstrably wide-ranging – it influences dozens of processes in the body. However, there is one important thing to understand: most of the benefits of supplementation are most pronounced when it is correcting a genuine deficiency. The lower your baseline 25(OH)D level, the greater the difference the right supplementation will make.

What vitamin D3 supports, according to available research:

• Immunity – some of the strongest evidence in the field; vitamin D activates immune cells and helps the body defend against infections
• Bone health – improves calcium absorption, supports bone density, and reduces the risk of falls in older adults
• Mental wellbeing – supplementation is associated with improved mood and a reduction in depressive symptoms, particularly in those with a deficiency; overall evidence remains mixed
• Reduced mortality risk in cancer – data suggests a modest beneficial effect; research is ongoing
• Support for diabetes – particularly in prediabetes and type 2 diabetes; vitamin D improves insulin sensitivity and glycaemic control
• Multiple sclerosis – supplementation may slow disease progression and improve quality of life in MS patients
• Overall wellbeing and performance – adequate vitamin D levels contribute to normal muscle function, energy, and recovery

For athletes, there is one additional rule worth noting – vitamin D deficiency directly impairs muscle performance and slows recovery, particularly in those who train predominantly indoors.

Vitamin D2 vs. vitamin D3

Vitamin D naturally occurs in two forms – ergocalciferol (D2) and cholecalciferol (D3), which differ in their origin and how effectively the body can utilise them.

Vitamin D2 comes from plant-based sources and mushrooms, whilst vitamin D3 is produced by the body itself through sun exposure and is found in animal products such as oily fish and egg yolks.

For supplementation, always choose vitamin D3 (cholecalciferol). Research consistently confirms that it raises 25(OH)D blood levels significantly more effectively than vitamin D2 (ergocalciferol) – and it is this level that indicates how much vitamin D your body actually has. D2 is plant-derived, but its ability to maintain optimal stores over the long term is lower. Vitamin D3 is available in a wide range of formats – softgel capsules, tablets, drops, and powder – with oil-based softgels amongst the most bioavailable options.

Tip: Explore our Immune Support category.

What's the best way to boost your vitamin D levels?

Of course, the very best way to get vitamin D is through daily sun exposure and drawing on vitamin D from sunlight. However, at least in our part of the world, this simply isn't possible all year round.

The second approach to topping up vitamin D is to incorporate foods that contain it into your diet – but even that isn't enough. Foods rich in vitamin D are surprisingly scarce. The richest sources include:

• oily fish such as salmon, mackerel, or sardines,
• fish oil,
• egg yolks, and
• certain varieties of mushrooms

Smaller amounts can also be found in liver and some cheeses.

The challenge is that the recommended daily intake of vitamin D – 15 µg per day according to EFSA – is practically unachievable through diet alone for most people. That is precisely why vitamin D3 supplements are the most reliable and practical way to keep your levels in check throughout the year.

Our range includes several forms of vitamin D – and each one serves its own purpose:

Standalone vitamin D3 in softgel capsules and tablets

The cornerstone of any supplement protocol – pure vitamin D3 (cholecalciferol) with no additional added ingredients. Oil-based softgel capsules are amongst the most bioavailable formats, whilst tablets offer simplicity and a long shelf life.

Available in vitamin D3 1,000 IU for everyday prevention and vitamin D3 2,000 IU for maintaining optimal levels year-round – the ideal choice for anyone looking to address a deficiency reliably and cost-effectively.

Liposomal vitamin D

Liposomal vitamin D is one of the more advanced supplementation formats, where the active ingredient is encapsulated in a liposomal or micellar shell composed of phospholipids. This shell protects vitamin D3 from degradation in the digestive tract and enables direct cellular uptake without dependence on digestive enzymes.

Research on advanced formats – including micellar D3 – suggests significantly higher absorption compared to standard tablets, particularly at lower doses (Solnier et al., 2024).

This enhanced bioavailability does come at a premium – liposomal vitamin D is amongst the more expensive options in the category.

Vitamin D drops

Vitamin D drops are a convenient supplementation format, particularly for those who have difficulty swallowing capsules or tablets – making them a popular choice for older adults and parents of young children.

They allow for easy drop-by-drop dosing, so you can tailor your intake precisely to your needs. Drops are typically added directly to food or a drink, meaning vitamin D is consumed alongside a meal – exactly the conditions needed for optimal absorption.

Combining vitamin D with other nutrients

Vitamin D3 and K2

An excellent choice for comprehensive bone and cardiovascular support. Vitamin K2 (MK-7 form) activates proteins that ensure calcium is deposited into bones rather than arterial walls. A biologically sound combination, particularly at higher D3 doses.

Calcium + vitamin D3 + K2

A triple combination that covers the entire chain: vitamin D3 ensures calcium is absorbed from the gut, K2 directs it to bones and teeth, and calcium provides the actual building material. A practical choice for anyone who doesn't eat dairy products regularly or has increased calcium requirements – such as older adults, post-menopausal women, or those with higher physical demands.

Omega-3 and vitamin D3 + K2

For athletes and active individuals looking to get the most from a single capsule. Omega-3 fatty acids reduce post-training inflammation and accelerate recovery, vitamin D3 supports muscle function and immunity, and K2 keeps calcium deposition on track.

Magnesium and vitamin D3

Magnesium is a cofactor for the enzymes that convert vitamin D3 into its active form in the liver and kidneys – without sufficient magnesium, the body cannot fully utilise D3. This combination makes the most sense when your diet isn't particularly rich in magnesium, which applies to most people with a busy, fast-paced lifestyle.

Vitamin C + D3

Two immune-supporting nutrients in one tablet. Vitamin C as a potent antioxidant, vitamin D3 as a regulator of immune cells – together, a practical and cost-effective support option for the winter months, when the body faces greater demands. A straightforward choice for those who don't want to manage multiple products at once.

How and when to take vitamin D

How should you take vitamin D?

Always with a meal containing fat – it's fat-soluble and absorbs better with food.

In practice: Take it with your largest meal of the day. Some individuals prefer taking it in the morning to avoid any potential disruption to sleep.

When should you take vitamin D – morning or evening?

A morning dose with breakfast is the safest option for most people. If you skip breakfast, move it to lunch or dinner instead.

How long should you take vitamin D?

For prevention, we recommend year-round supplementation, or at minimum from October through to April. When correcting a confirmed deficiency, saturation typically takes 2–3 months.

What is the daily dose of vitamin D for adults?

This is one of those questions with no universal answer – it depends on who you are and what you're looking to address. That said, the general rule is: the lower your baseline level, the higher the starting dose you'll need.

• For most adults, 1,000–2,000 IU per day serves as reliable year-round deficiency prevention.
• Athletes, those with a higher body weight, or those who spend most of their time indoors tend to fall in the 2,000–4,000 IU range.

The most accurate answer, however, can only come from a blood test – measure your 25(OH)D level and set your daily vitamin D dose based on actual need, not guesswork.

Vitamin D for children and newborns

Vitamin D is essential from the very first days of life. Newborns and infants receive very little of it – breast milk contains minimal amounts and sunlight is essentially not a viable source for them. Yet in early life, vitamin D plays a crucial role in the healthy development of bones, teeth, and the immune system.

Vitamin D for newborns is typically administered from the first days of life in the form of drops – most commonly at a dose of 400–500 IU per day, regardless of the time of year. Paediatricians routinely recommend this supplementation for both breastfed and formula-fed infants. Always consult your paediatrician for precise dosing guidance.

Vitamin D for children remains important after weaning and throughout childhood. Recommended amounts increase with age:

• Infants and toddlers (up to 1 year): 400–500 IU per day
• Children aged 1–10: 600–1,000 IU per day
• Older children and adolescents: 1,000–2,000 IU per day

For the youngest children, drops are the most suitable format – they allow for precise dosing and can easily be added to milk or food. Older children can manage chewable tablets or capsules. As with adults, supplementation makes the most sense from October through to April, but ideally year-round.

Vitamin D: Overdose

At typical doses of 1,000–4,000 IU per day, the risk of overdose is minimal – and the vast majority of products in our range fall within this bracket.

Problems only arise at extremely high doses exceeding 50,000 IU per day over a prolonged period, where blood calcium levels can rise and cause nausea or fatigue. This is, however, a scenario that simply won't occur with normal supplementation.

How to choose the best vitamin D

When making your choice, look for three things: the D3 form (cholecalciferol, always preferred over D2), a dose that matches your needs, and a combination of ingredients aligned with your goal. The range below is ordered by bestsellers and ratings – you'll find options for everyday prevention as well as more comprehensive support.

In Summary

Vitamin D3 is the most thoroughly researched and biologically effective form of vitamin D, with clearly demonstrated effects on immunity, bone health, and muscle function. Whether you're taking it preventatively or correcting a confirmed deficiency, it works reliably for everyone.

Choose your vitamin D3 at BodyWorld based on your preferred format – standalone D3, a combination with K2, omega-3 with vitamin D, or D3 with magnesium – and make it a firm part of your daily routine. And don't forget to check out our latest deals and discounts.