Vitamin D


Why is vitamin D so important?

Vitamin D is essential for strong, healthy bones and teeth. You can get it from sunlight on the skin and diet, and it works to support your bones by aiding the absorption of calcium. Most people know about the importance of calcium for healthy bones and teeth, but not many people know that your body struggles to absorb calcium without vitamin D. This is most important in early childhood when growing bones are developing. 

Low levels of vitamin D mean your bones aren’t getting the support they need to develop properly. Before you turn 30 is the best time to build up your bone density, as the density of your bones decreases after 30, impacting balance and muscle strength. This is why older people are at an increased risk of bone fractures following falls.* After you turn 30, vitamin D intake is still important to ensure you maintain your bone density as you age.

*For 60 years and over: Vitamin D helps to reduce the risk of falls associated with loss of balance and muscle weakness. Falling is a risk factor for bone fractures among those who are 60 and over. Taking 20 mcg of vitamin D daily can reduce the risk of falling.  

What causes low levels of vitamin D?

Vitamin D is found in food, but only in small amounts, meaning you can't get the right amounts of vitamin D from your diet alone. The main source of vitamin D is from the sun. 

Who’s at risk of low vitamin D levels?

Some groups of the population are more vulnerable than others and more likely to have low levels of Vitamin D:

  • Infants
    • Children under 4
    • Pregnant and breastfeeding women
    • Over 65s
    • People with low exposure to the sun, eg those who often cover their skin, those who are housebound or confined indoors for a long time
    • People with darker skin, especially people of South Asian, African, or Afro-Caribbean background

Natural sources of vitamin D

The main source of vitamin D is from sunlight. Even though it is hard to obtain the right levels from your diet, there are some foods that contain high levels of vitamin D. Foods with higher levels of vitamin D include:

  • Fatty fish, like tuna, mackerel, and salmon
    • Foods fortified with vitamin D, like some dairy products, orange juice, soy milk and cereals
    • Beef liver
    • Cheese
    • Egg yolks

Which supplements should I take?

The most recent advice says that all adults should take a 10 mcg/400iu vitamin D supplement during the months when we go out in the sun less.

You don’t need to have vitamin D deficiency to think about taking a vitamin D supplement. If you have concerns about your health, or if you’re vitamin deficient, we recommend speaking to your Doctor. 

Vitamin D2 & D3

The two most important forms of vitamin D you can find are D2 and D3. D2 is produced by plants, and D3 is the one made by your skin when you get enough sunlight. Research shows that D3 is generally better absorbed than D2, so we suggest that you choose a vitamin D3 supplement or one that contains enough of both.

Vitamin D3 supplements are usually suitable for vegetarians (see each pack for details) but not for vegans, while vitamin D2 products can be suitable for vegans.

Vitamin D supplements

There are many different blends of vitamin D and other supplements to suit individual needs. At Boots we offer a large range of products that contain vitamin D, along with other supplements. 

How to understand units

You might find several symbols and units used to describe the vitamin D content of a product. Vitamin D is measured in micrograms. This can be written as mcg or µg. ‘µg’ is the symbol you should find in nutrition tables on packs of vitamin D supplements.