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You’ve probably heard of vitamin D before, but what exactly is it, and why is it so important?  

The active form of Vitamin D – Vitamin D3 (cholecalciferol) – is made by the skin by the action of UVB irradiation on a form of cholesterol in the skin. People living in the northern hemisphere, or who are not outside often, are mostly covered (by clothes or a UVB blocking suncream), or have dark skin are at greater risk of low Vitamin D3 levels (1). 

Vitamin D is critical to health as it acts to mediate calcium and phosphorus uptake in the gut and is also fundamental to the maintenance of bone density – a super important point for us women. Vitamin D deficiency is associated with some forms of cancer (colon, colorectal, breast and prostate), PCOS (Polycystic Ovarian Syndrome), diabetes, hypertension and osteomalacia, in addition to rickets in children (2). 

Foods that contain some Vitamin D3 include oily fish, eggs, red meat and liver, however, these sources are secondary to the action of sunlight on skin (1). So the best way to top up your vitamin D levels is 15-20 minutes of unprotected sun exposure, but unfortunately for those of us in the Northern hemisphere, the sun’s rays on a sunny winter’s day aren’t strong enough so many of us need to top up using supplements.  

Public Health England estimates that 1 in 5 adults and 1 in 6 children may have low Vitamin D levels – a whopping 10 million people in England (3). Due to the prevalence of Vitamin D deficiency I recommend most of my clients (especially my Nourished Mums) take a good quality D3 supplement. Requirements obviously vary between individuals but Solgar liquid Vitamin D3* is a good option. What does this mean for your family? Well, the UK DoH (Department of Health) recommendations are… 

  • Children (from 1 years of age) and adults receive a daily supplement of 10mcg (especially over the winter months).  
  • It is really important that pregnant women have sufficient vitamin D levels throughout pregnancy to ensure baby is born with adequate levels, and during the postpartum period to replenish stores depleted during pregnancy.  
  • The level of vitamin D in breastmilk will depend on the mother’s intake and vitamin D stores, so as a precaution they also recommend breastfed babies be supplemented with 8.5-10mcg – always speak to a healthcare professional before supplementing your baby. Formula-fed babies do not require supplementation as formula milk is fortified with vitamin D (4). 

Finally, vitamin D is stored in our body fat, so if you are lucky enough to go on a sunny summer holiday, the vitamin D boost should top you up for a few weeks/months. Another excuse to go on holiday!  

*Solgar vit d liquid: 62mcg (2500IU) per 0.5ml which is 15 drops so 10mcg is 2-3 drops  


  1. National Institutes of Health. 2019. Vitamin D. Available at: (Accessed: 31st January 2020) 
  2. Nair, R., Maseeh, A. 2012. Vitamin D: The “sunshine” vitamin. Journal of Pharmacology & Pharmacotherapeutics, 3 (2), 118-126 
  3. 3. 2016. PHE publishes new advice on vitamin D. Available at: (Accessed: 31st January 2020) 
  4. 4. NHS. 2017. Vitamin D. Available at: (Accessed: 31st January 2020) 

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