- Nutritional Vitamins & Supplements
Food Sources of Vitamin D
Vitamin D is known as the ‘sunshine vitamin’ – your body can synthesize Vitamin D internally, but if you live in cooler Northern climates your sun exposure alone may not be sufficient to meet your requirements – the 42 degrees latitude line is often cited as a cut-off point for sufficient exposre, but other factors are also important such as use of sunscreens, personal skintone and melanin levels, and how much skin is frequently exposed to the sun. For all these reasons, it is important for most of us to ensure good dietary intake of Vitamin D for optimal health.
Vitamin D is unusual, in that it functions as a hormone in the body. It is needed for muscularskeletal and nerve health within the body, and deficiencies are linked to rickets/osteomalacia, as well as fractures, mental health problems, fatigue and chronic pain. Because of the multiple routes for Vitamin D to enter or be created within the body, deficiencies can be hard to pinpoint - one way to be sure is to request a blood test from your primary care provider to find out if your 25-OH-vitamin D is within normal reference ranges (>30 ng/mL or >75 nmol/L).
Some foods rich in Vitamin D include fish oils – but these need to be in a pure and unrefined form, because sometimes fish oils sold as a supplement have the Vitamin D removed – you need to check labels carefully. Oily fish like salmon and mackerel are good Vitamin D foods, as are less commonly eaten fish like herring. As it’s a fat soluble vitamin, it needs fat as a carrier. Red meats like beef also provide a food source of Vitamin D.
For vegetarians, milk can be a good source of Vitamin D, but mainly because most commercial milk supplies are fortified with it, rather than it occurring naturally. This is important to understand, because raw and unpasteurised milk that might be preferred by wholefood enthusiasts will lack this fortification, and also it is not commonly done to milk destined for manufacturing processes such as cheese. There is also some Vitamin D in egg yolks, so vegetarians can get it from those too.
especially those who might not get adequate sunlight exposure, it’s harder to
get or create enough Vitamin D, so supplements might be advisable. Vitamin D is actually composed of more than
one chemical substance, one of these Vitamin D2, called ergocalciferol can be
obtained from vegan sources like yeast and mushrooms. There is debate around
the metabolic pathways and specific utilization of D2, as opposed to the more
common dietary source D3, within the body – but D2 appears to be sufficient in
many cases. For
vegans looking for supplementation, it should also be noted that many
supplements are delivered in non-vegetarian gelatin based capsules, and the
commonest form of D3 (cholecalciferol)
supplement is derived from lanolin in sheep’s wool.