Most of us are aware that we need sun exposure to keep our levels of vitamin D topped up. Oily fish, eggs, and mushrooms provide vitamin D in the diet, but it is the action of the sun on our skin which gives us most of our vitamin D.
In the UK, because of its Northern latitude the sun is not strong enough between October and March for this process. In the summer months, even wearing sun block, we should naturally top up our vitamin D stores. However, it might not be quite that simple.
A growing body of research suggests that many of us are still low in vitamin D even during the summer months:
- A study in women reported 54 % of premenopausal South Asian women had severe deficiency (25(OH)D < 25 nmol/l) with similar figures for post menopause during the summer months (1).
- Similarly, a more recent study found over 70% of adults of any age with darker skin types and over 50% of all older adults had insufficient levels over the summer months (2).
- Children and teenagers are also at risk with research showing 59% of South Asian girls and 23% of South Asian boys aged 12-15 years in Northern UK had severe vitamin D deficiency which persisted year round (3).
For those who spend most of their time inside, older adults, or those of any age with darker skin (which naturally need more sun exposure to make enough vitamin D) the message is clear - A good vitamin D supplement may be needed all year round.
The Viridian Nutrition’ Vitamin D range uses vegan vitamin D3 derived from lichen not lanolin which is derived from sheep’s wool, and incudes a variety of strengths. For those who prefer liquid, vitamin D drops are also available for adults and children.
More about the author: Corin has a Degree in Clinical Herbalism, and a Diploma in Nutritional Therapy. Corin has a wealth of clinical experience in natural and wellbeing, and using nutrition and herbs to optimise overall wellness.
Author: Corin Sadler, BSc DipION, FDSc is a Medical Herbalist and Nutrition Manager at Viridian Nutrition.
References
1. Darling, AL, Hart, KH, Macdonald, HM, et al. (2013) Vitamin D deficiency in UK South Asian Women of childbearing age: a comparative longitudinal investigation with UK Caucasian women. Osteoporos Int 24, 477–488
2. Goddard A, Watson A, Tilbury R, Corfe BM, Fairley A. Circannual prevalence of vitamin D insufficiency in older and minoritized ethnic adults in Northern Britain: screening outcomes from a clinical trial. Eur J Clin Nutr. 2026 Aug;80(8):855-858.
3. Marjanovic EJ, Farrar MD, Kift R, Mughal MZ, Webb AR, Rhodes LE. Sun Exposure Behaviour and Vitamin D in South Asian Compared with White Caucasian Adolescents: Prospective Cohort Study. Nutrients. 2026 Jul 27;18(15):2443. Sun Exposure Behaviour and Vitamin D in South Asian Compared with White Caucasian Adolescents: Prospective Cohort Study
The information contained in this article is not intended to treat, diagnose or replace the advice of a health practitioner. Please consult a qualified health practitioner if you have a pre-existing health condition or are currently taking medication. Food supplements should not be used as a substitute for a varied and balanced diet.
