Vitamin D, do you need it?

By Gwen Bastian-Enright, MSc, dipNT, mNTOI

Vitamin D is obtained mainly in two ways, it is made in the skin after being exposed to sun (D3), and through the intake through the diet (mainly D3 but D2 in mushrooms) (NIH, 2019).

Many factors affect the amount we require, such as time of year (amount of sun), latitude, skin pigmentation, time spent outdoors and diet – in Ireland most people do not consume top food sources of vitamin D such as wild caught oily fish, egg yolks, liver, mushrooms like shiitake, and fortified foods (Jones, 2019). Vitamin D is important for many functions in the body, such as bone, mental and immune health.

You may be familiar with a lack of vitamin D contributing to rickets – something that is actually on the rise again in Ireland and the UK,
and many Irish people are deficient in this important vitamin. In fact, Cashman et al. (2013) stated that 40.1% of the Irish population has vitamin D levels below that indicated for optimum bone health. But vitamin D is needed for so much more than just bone health, for example:

Depression: A review of 61 studies has found that people with the lowest levels of vitamin D have the greatest risk of depression (Menon et al., 2020) and while the exact mechanism is not yet known it is proposed that vitamin D supplementation can be beneficial.

PMS: A 2019 study suggests that optimising vitamin D levels may help women with
premenstrual syndrome (PMS) as women with PMS appear to have lower levels during the luteal phase of their cycle (Heidari et al., 2019). In combination with vitamin E, vitamin D appears to be an effective, safe and affordable treatment for PMS (Dadkahah, Ebrahimi and Fathizadeh, 2016).

NAFLD: A very recent meta-analysis (Liu et al., 2020) suggests that the presence of non-alcoholic fatty liver disease (NAFDL) may be associated with low vitamin D status, and thus people with low vitamin D status may benefit from supplementation to reduce risk of NAFDL. Supplementation may be beneficial not only in winter, but also in summer (Hill et al., 2005).

The NHS recommend that everybody over the age of one should take a vitamin D
supplement of 10mcg a day from October to the end of March (NHS, 2016), which is 400iU but bear in mind that this is only the RDA, which is set to avoid a deficiency and not aimed at optimum health. Supplement form – ideally this should be D3, and can come in the form of sprays, capsules or drops. Ideally, supplementation should stay well below the upper safe limit of 4,000iU daily without testing for levels, you can ask your GP to check your levels, but
please be aware that many labs will not test for vitamin D.

Personally, I really like the BetterYou sprays as they are easy to administer (for babies and children too) but we also have drops and capsules available in store from Viridian and Terranova, so there is something for everyone.

References