PART 1. How much Vitamin D do you need to take and what type?

Adults and children > 1 year: 10µg/day in October – April in the UK

👩‍⚕️Some people who have greater vitamin D needs may need to take more if recommended by their healthcare professional – always consult your GP or registered dietitian first.

🍼What about babies?

🍼As a precaution, all exclusively breastfed babies under one year should have a daily 8.5-10mcg vitamin D supplement to make sure they get enough.

🍼However, babies who have more than 500ml (about a pint) of infant formula a day don’t need a vitamin D supplement as the formula is already fortified.

What Type?

👩‍⚕️Vitamin D3 is the biologically active form made in our bodies or found in animal foods, plant-sourced D2 could be less biologically active. If you’re vegan it is possible to get a D3 vegan supplement in health food stores.

👩‍⚕️Vitamin D is best absorbed with fat so take your supplement with meals.

Can I not just get Vitamin D from my diet rather than taking a supplement?

👩‍⚕️Vitamin D is found in foods but just not in large amounts

👩‍⚕️We are recommended to have 10mcg per day.

🍳1 large egg – 1mcg. Around 1/10th of the recommended amount you need for the day.

🐟A 100g portion of salmon 13mcg of vitamin D (but it is slightly unrealistic to suggest we all have salmon every day to meet our Vit D needs and we are recommended to limit fish consumption to 4 portions a week to limit exposure to pollutants.)

🍖Meat, fat, liver and kidney-  0.1-1.5mcg/100 g. Again you would need to eat 1kg of these products/ day to hit the vitamin D recommendation, which is well above the dietary recommendations for meat intake and also saturated fat.

🍄Mushrooms – like humans mushrooms can make their own vitamin D using sunlight, however, the mushrooms we buy in the supermarkets are grown in the dark so are not a good source.

🍄Supermarkets are now selling mushrooms fortified with vitamin D, with 4-5 mushrooms proving 100% of your daily requirement. Note that these contain Vitamin D2 which is less biologically active than D3 so you may need to have more to meet 100% of your daily requirements.

🍄🍳🍖🐟Irrespective of whether you decide to have these foods to boost your vitamin D intake – these foods are rich in many nutrients and their benefits are not limited to their Vitamin D content.

💊 Do I need to be careful not to take too much?

💊 It is recommended not to take more than 100µg/ day (4000 IU). Too much vitamin D can lead to bone demineralization, increased risk of cancer and damage to liver and kidneys. Be aware if you’re already taking a multivitamin that you don’t go over 100µg/ day of vitamin D.

💊 There is no harm in having foods that are rich in Vitamin D and also taking your recommended daily supplement as it is unlikely you will have too much.

Part 2. Can Vitamin D prevent colds?

☀️This week for Q&A Wednesday we are answering questions on vitamin D supplementation.

☀️See part one for the amounts and types of vitamin D recommended for adults and children, foods sources of vitamin D.

☀️See part three for information on why we supplement between October and April and not the whole year

🤧In 2017 a systematic review and meta-analysis (SR+MA) reviewed the link between vitamin D intake and the occurrence of colds and flu. This is the gold standard type of research which is the best way of gathering all the information on a topic.

🤧BUT it is worth noting that a SR + MA is only as good as the studies it includes, so be critical when reading them. This one in particular excluded poor quality studies so the results can be looked at as more reliable.

🤧All the studies included in the review compared the effect of taking a vitamin D supplement to a dummy (placebo) pill and they were “double blinded” this means that neither the doctor or participants knew who was taking which pill.

The results:
🔬 Vitamin D supplementation was found to reduce the risk of cold/ flu symptoms by 12%.
🔬 Additionally, those who took daily or weekly doses had greater protection against colds and flu than those who took large one-off doses.
🔬Protective effects were stronger for people with low levels of vitamin D at the start of the study, and also people with asthma.
🔬The researchers concluded that vitamin D supplementation could be useful in the prevention of colds and flu and no adverse effects of supplementation were observed.

Part 3. THE SUMMARY

Key points: 

☀10mcg = 400 IU  

☀Adults and children > 1 year need 10mcg supplement/ day. 

☀Children < 1 year + exclusively breast fed need an 8.5mcg-10mcg supplement / day.

☀Children < 1 year + having formula milk – if having around 1 pint of formula/day the babies will not need an extra Vit D supplement as the formula is already fortified.

☀Some people who have greater vitamin D needs may need to take more if recommended by their healthcare professional – always consult your GP or registered dietitian first.

☀Why only October –April?

☀Vitamin D is one of the few nutrients the body can make by itself. The action of sunlight on our skin turns cholesterol into a compound which travels to the liver and kidneys where it is converted to the type of vitamin D that is used by our bodies. 

☀However in the UK we are not exposed to enough sunlight during the winter months (don’t we just know it!) for the body to make sufficient amounts, so during this time we need to supplement.

☀NOTE: If you spend a lot of time indoors, have darker skin, or wear clothes that cover most of your body during the summer, you may need a vitamin D supplement all year round.

☀Supplements are found in different forms including tablets and oral spray. With oral sprays make sure to always check the dose as some have higher dosages.