(Seasonal affective depression - SAD)

Winter tiredness due to lack of  sunlight is known as seasonal affective depression (SAD) and the Winter blues.


It can be prevented by taking vitamin D supplements and by using a sun light. Supporting the immune system in this way may also increase resistance to Covid.

Taking vitamin D unsupported by vitamin K can cause calcification of the blood vessels and consequently increase the risk of ischaemic heart disease. Also, combining with vitamin K reduces the required dose of vitamin D.

Current government advice is that adults should take at least 24 mcg (1000 international units) of vitamin D3 a day. 


A recommendable vitamin D preparation is K-Right, Jarrow (60 capsules), one capsule to be taken daily.    This is the only vitamin D preparation that has been found  at this clinic to test consistently effective .  


It is available from  iHerb - cost about £30 including postage.

Content of each K-Right softgel

Vitamin D3 (Cholecalciferol)      50 micrograms (2000 i.u.)  Vitamin K1 (phylloquinone)      500 micrograms

Vitamin K2 (MK-4).                 1500 micrograms

Vitamin K2 (as naturel MK-7).   180 micrograms


Do not self-medicate with vitamin K if you are pregnant, trying to conceive or taking anticoagulants such as warfarin and coumadin. 



Research in Scandinavia has indicated that taking vitamin D supplements does not altogether prevent tiredness due to deprivation of sunlight in winter. In view of this, it is advisable to use a sunlight during winter in addition to taking vitamin D supplements.   

A suitable sunlight is the  LED Energy Lamp, 

HappyLight Lucen, Model: VT22 is obtainable from 

This model, which is made in China, has a US plug, so that a US-UK adaptor plug is needed, (e.g., Go, 315Z, Ref.554, BS 8546). In any event, the adaptor should have a flat insert face without an indent for a protruding US plug.  

About ten minutes a day exposure to a sun light is normally sufficient.









© 2020 by Integrated Medical Centre, London, England. All rights reserved.

Registered member of The Complementary Medical Association.

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