As the days start to get cooler and the amount of sunshine starts to fade, our ability to naturally get the right amount of vitamin D from the sun begins to diminish. Even in the summer months, particularly in the northern hemisphere it is particularly difficult to get your full quota of vitamin D. In fact vitamin D deficiency is prevalent in the UK, with 1 in 5 adults having low levels.
We live in a time where sun exposure is considered by some to be a health menace. In an effort to reduce skin cancer, we have encouraged people of all ages to wear sunscreen and protective clothing and spend more time in shaded areas. Sensible sun exposure without sunscreen it a good way to up intake of vitamin D without burning. This doesn’t unduly raise the risk for skin cancer.
Yet the advanced cancers linked to vitamin D deficiency such as colorectal, ovarian, breast, lung, prostate and thyroid cancer far outweigh skin cancer diagnosis. More than three fourths of these advanced cancer patients have low levels of vitamin D. Research suggests that vitamin D has anti-tumour properties, regulating genes involved in the multiplication and spread of cancer cells.
Vitamin D was mistakenly categorised as a vitamin, in fact it isn’t a vitamin at all. It’s a steroid hormone that influences virtually every cell in your body. From your heart to your brain, to your immune system, maintaining optimal vitamin D levels is incredibly important. Vitamin D is a crucial anti-inflammatory hormone. Vitamin D is necessary for insulin secretion, so is an important component of glucose metabolism.
Those individuals with a low blood (serum) level have a higher risk of cardiovascular disease. Vitamin D prevents the migration of calcium to cardiovascular tissues from the bones, increases HDL cholesterol and reduces LDL cholesterol. It helps control the hormone renin, which regulates blood pressure and reduces the growth of vascular smooth muscle which narrows arteries, as well increasing immune tolerance and reducing inflammation.
Supplementing with vitamin D is an important health essential. The type of vitamin D supplement is critically important, doctors often prescribe vitamin D2 (ergocalciferol) supplements, instead of D3 (cholecalciferol). There are several biological mechanisms that contribute to the superior absorbability and efficacy of Vitamin D3. In the liver, thanks to a particular hepatic enzyme, vitamin D3 is more readily metabolized into a bioactive form of vitamin D, which is easily converted to its hormone form in the kidneys. It takes much longer to make this hepatic conversion with vitamin D2. Clearly, these forms of vitamin D are simply not the same, therefore the superiority of vitamin D3 supplements is important to understand.
There is no recommended intake in the UK except the elderly (400 iu or 10 mcg per day). The concern around toxicity of vitamin D at high levels is due to the potential of excess calcium, which can form plaques in blood vessels. The expert panel on vitamins and minerals in the UK acknowledges 4000 iu per day as a safe dose. Human trials have shown 10,000 iu per day to be safe and a 5 year study suggests 40,000 iu is unlikely to be toxic.
Foods that provide vitamin D include:
• Fatty fish, like tuna, mackerel, and salmon.
• Foods fortified with vitamin D, like some dairy products and soy milk.
• Beef liver.
• Egg yolks.
Vitamin D may affect blood sugar levels. Caution is advised if you are taking diabetes medication by mouth or insulin, you should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary. Vitamin D may affect blood pressure and associated medications. Vitamin D may interfere with the way the body processes certain drugs using the liver’s “cytochrome P450” enzyme system. As a result, the levels of these drugs may be altered in the blood and may cause altered effects or adverse reactions. The same reactions apply to herbs and other supplements for blood glucose control, blood pressure and other support systems. Consult your doctor and pharmacist about possible interactions.