Seven health benefits of Vitamin D and the sun, including fat loss
The sun, not something we get the pleasure of seeing that often in the UK is it? however, as I write this short article on the health benefits of the golden ball in the sky I can say I am gloriously basking (burning) in it.
The sun just seems to make everything better doesn’t it? it puts everyone in a good mood, I imagine in London it may even make people say hello to one another…but then again, maybe not.
Vitamin D, also known as the “sunshine vitamin” is unique as it can be made in the skin when exposed to sun light (Nair and Maseeh, 2012).
We can get Vitamin D via food, however to get sufficient levels you would have to consume approximately 6 litres of milk or 150 eggs...a day.
depending on your skin tone and where in the world you live you can sit in the sun for approximately 20 minutes (without sun block).
In the UK we have a limited window of opportunity to top up our Vitamin D levels as it depends on the height and angle of the sun. This tends to mean the best time to get Vitamin D is between April and September in the peak hours of the day.
I have started using an app called ‘Dminder’. The app helps you calculate current Vitamin D levels and advises you on when and where you can get Vitamin D from the sun, based on your personal details, including height, weight and skin tone.
It is estimated over 50% of the worlds population is deficient in Vitamin D (Nair and Maseeh, 2012) which is due mainly to a lack of exposure to the sun. Wearing factor 30 sun cream or higher reduces Vitamin D synthesis by 95% (Matsuoka et al., 1987) and those with darker skin may have to be exposed to the sun for three to fives times that of pale skinned people (Clemens et al., 1982).
Vitamin D deficiency has been linked to increased risk of mortality (Nair and Maseeh, 2012). A further issue is without Vitamin D, only 10-15% of calcium is absorbed which can lead to poor bone health, a double health whammy considering one of the most likely to suffer with low Vitamin D levels are the elderly.
Further associations with low Vitamin D include:
- Cardiovascular disease
- Inflammatory bowel diseases (IBD)
As well as the elderly, vampires (including myself) and darker skinned people, others at risk of low Vitamin D are people who are housebound, those that have to cover the majority of their body up (e.g. cultural and religious reasons), and people who are classed as obese (>30 BMI).
The reason people with a high BMI are more likely to be Vitamin D deficient is the greater subcutaneous fat (under the skin) sequesters (holds on to) more of the vitamin and alters the amount released into circulation.
There are several benefits to increased Vitamin D levels including
Improves bone health by increasing calcium absorption
Improves immune system
Improved cardiovascular health (Nair and Maseeh, 2012)
Reduces depressive symptoms (Shaffer et al., 2014)
Potentially helps to manage blood glucose in older adults
Potentially improves strength (Tomlinson et al., 2015)
Potentially improves fat loss (Carrillo et al., 2013; Khosravi et al., 2018; Ortega et al., 2008)
There are a few small studies which have looked at the impact of Vitamin D on weight loss. Ortega et al. (2008) looked at Vitamin D levels in overweight or obese women between the age 20-35 and found women with higher Vitamin D levels responded more positively to a hypocaloric diet (calorie deficit), losing more body fat (-1.7kg) compared to those with low Vitamin D levels (-0.5kg). Similar results were found in a 6-week study by Khosravi et al. (2018) who found women who were given a Vitamin D supplement lost more weight on average (-1.6kg) compared to those who were given a placebo (+0.05kg). Carrillo et al. (2013) not only found an association between increased Vitamin D levels and reduced waist-to-hip-ratio but increased power output too in resistance training sessions in overweight and obese participants.
These studies don’t say with certainty that increased Vitamin D will lead to greater weight loss however they do give a compelling glimpse in to how they could be associated and a great excuse to book a holiday.
Of course, the sun itself won’t make you lose weight, I mean Mexico is rather sunny and they are one of the most overweight nations in the world. It is after all energy balance and Calories which will determine your weight, how Vitamin D alters our behaviours which leads to a Calorie deficit who knows. Perhaps Vitamin D makes us feel happier leading to reduced emotional eating, perhaps the sun reduces our appetite leading to us eating less, perhaps neither of my theories are correct however there is absolutely no doubt we should be getting more Vitamin D for our health, both physically and mentally.
· We get most of our Vitamin D from the sun
· In the UK we can only get Vitamin D from the sun in the spring and summer months
· Sun cream will reduce your Vitamin D synthesis by up to 95%
· Sit out in the sun for 20-30 mins a day when possible
· During the winter I recommend you supplement with Vitamin D (2500-4000iu/day)
· Vitamin D deficiency is linked to poor bone health, CVD, Type 2 diabetes etc
· The more body fat you have the more sun exposure you may need
· Same goes for the darker your complexion
· Benefits of increased Vitamin D include improved immune system, mood, strength and possibly fat loss
· Download ‘Dminder’
Carrillo, A., Flynn, M., Pinkston, C., Markofski, M., Jiang, Y., Donkin, S. and Teegarden, D. (2013) 'Impact of Vitamin D Supplementation During a Resistance Training Intervention on Body Composition, Muscle Function, and Glucose Tolerance in Overweight and Obese Adults.' Clinical nutrition (Edinburgh, Scotland), 32(3), 2013 Jun,
Clemens, T., Adams, J., Henderson, S. and Holick, M. (1982) 'Increased Skin Pigment Reduces the Capacity of Skin to Synthesise Vitamin D3.' Lancet (London, England), 1(8263), 01/09/1982,
Holick, M. (2007) 'Vitamin D Deficiency.' The New England journal of medicine, 357(3), 07/19/2007,
Khosravi, Z. S., Kafeshani, M., Tavasoli, P., Zadeh, A. H. and Entezari, M. H. (2018) 'Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study.' In Int J Prev Med. Vol. 9. http://dx.doi.org/10.4103/ijpvm.IJPVM_329_15
Matsuoka, L., Ide, L., Wortsman, J., MacLaughlin, J. and Holick, M. (1987) 'Sunscreens Suppress Cutaneous Vitamin D3 Synthesis.' The Journal of clinical endocrinology and metabolism, 64(6), 1987 Jun,
Nair, R. and Maseeh, A. (2012) 'Vitamin D: The “sunshine” vitamin.' In J Pharmacol Pharmacother. Vol. 3. pp. 118-126. http://dx.doi.org/10.4103/0976-500x.95506
Ortega, R., Aparicio, A., Rodríguez-Rodríguez, E., Bermejo, L., Perea, J., López-Sobaler, A., Ruiz-Roso, B. and P, A. (2008) 'Preliminary Data About the Influence of Vitamin D Status on the Loss of Body Fat in Young Overweight/Obese Women Following Two Types of Hypocaloric Diet.' The British journal of nutrition, 100(2), 2008 Aug,
Shaffer, J. A., Edmondson, D., Wasson, L. T., Falzon, L., Homma, K., Ezeokoli, N., Li, P. and Davidson, K. W. (2014) 'Vitamin D Supplementation for Depressive Symptoms: A Systematic Review and Meta-analysis of Randomized Controlled Trials.' Psychosom Med, 76(3), Apr, pp. 190-196.
Tomlinson, P., Joseph, C. and Angioi, M. (2015) 'Effects of Vitamin D Supplementation on Upper and Lower Body Muscle Strength Levels in Healthy Individuals. A Systematic Review With Meta-Analysis.' Journal of science and medicine in sport, 18(5), 2015 Sep,