Are Your 'Sunshine Vitamin' levels Low?

Am I getting enough Vitamin D?

• By Emer Delaney - Dietitian - Are your ‘sunshine vitamin’ levels low? Discover why you need vitamin D, how to get more and what to do if you're concerned about your levels...

  

  Why do we need Vitamin D?

  Vitamin D is made in our skin via direct exposure to sunlight. Our liver and kidneys then convert it into a form we can use. Vitamin D is extremely important for strong bones and teeth, as it helps us absorb the calcium we eat and it also controls the amount of calcium in our blood.  It’s really important that our vitamin D levels aren’t low or our body won’t absorb the calcium we eat.  

  There aren't any visual signs of vitamin D deficiency. If our levels are very low and we are severely deficient, we are at risk of developing weaker bones which is a condition known as osteomalacia. Severe deficiency in children may result in soft skull or leg bones and their legs may look curved or bow-legged, which is a condition called rickets.  

  Vitamin D levels explained

  Vitamin D blood ranges	Classification
  Under 25nmol/L	Deficient
  25 - 50nmol/L	Insufficient
  50-75nmol/L	Sufficient
  Over 75nmol/L	Optimal

  How much sun do we need? 

  During the summer months, approximately 20-30 minutes of direct sunlight two to three times a week should be enough for a fair skinned person to make the vitamin D they need.  For the elderly and darker skinned people, exposure time or frequency needs to be increased two to tenfold to get the same level of vitamin D synthesis as fair skinned individuals. 

  A word of caution though, too much sun exposure can be damaging due to the risk of developing skin cancer. Only spend a small amount of time in the sun without sunscreen either early in the morning or late in the afternoon and the rest of the time be sure to cover up and avoid any chance of sunburn. 

  Amount of sun required to compensate for 49 days of no exposure

  Skin type	Minutes of July sun required
  Fair	10 - 12 mins
  Asian	30 mins
  African/ Afro-Caribbean	120 mins

  What affects our Vitamin D levels?

  Several different factors can affect our vitamin D levels such as skin pigmentation, age, season, clothing and use of high factor sunscreens. As elderly people have thinner skin they are unable to make as much of the vitamin as younger people. Also, the position of the UK means that 90% of it lies above the latitude that permits exposure to the sun rays necessary for vitamin D synthesis. The southern part of the country is marginally better positioned for vitamin D synthesis (the closer you are to the equator the better). All of these factors will have an effect on our levels.

  Approximately 60–70% of the UK adult population have insufficient levels of vitamin D in winter and spring and 16% are considered deficient. At the moment, there are no recommendations for daily intake. Whilst UK recommendations have not been set for the general population, some groups are at higher risk for developing deficiencies.  These include:

  • Pregnant and breastfeeding women
  • People who have darker skin, such as those of South Asian, African or Afro-Caribbean descent
  • Men and women who are over 65 years of age
  • Babies and children aged six months to five years 
  • Adults who stay out of the sun or cover up when outside 

   Vitamin D in our diet

  Foods that naturally contain vitamin D include oily fish such as mackerel, sardines, tinned salmon, herring and kippers.  Some foods are fortified with small amounts of vitamin D, including breakfast cereals, infant formula and margarine. There are smaller amounts found in eggs and some red meats, such as duck, goose, pheasant and venison however, the exact amount is unknown. Breast milk also contains vitamin D and mums should make sure they aren’t deficient as this will affect the levels in their milk.  

  Vitamin D-rich foods

  Food per portion	Vitamin D content
  Kipper (140g)	35µg
  Herring (140g)	31.5µg
  Mackerel (140g)	24.5µg
  Tinned salmon (140g)	17.5µg
  Sardines (140g)	10.5µg
  Duck eggs (2)	3.75µg
  Hen eggs (2)	2.5µg

Minerals for You

Vital minerals

• By Jo Lewin - Associate nutritionist

The human body uses minerals for many things, including keeping bone and blood cells healthy. Minerals work along with vitamins as essential components in enzymes and coenzymes. If an essential mineral is lacking, your body won't be able to work at its best. For example, zinc is necessary for the enzyme which activates vitamin A for good eyesight and without it, vitamin A cannot be used properly by the body. This deficiency may result in night blindness.
 

Calcium

Calcium is important in the activity of many enzymes in the body and is essential for building and maintaining bones and teeth. The contraction of muscles, release of neurotransmitters, regulation of heartbeat and clotting of blood are all dependent on calcium. Periods of growth, pregnancy and lactation may require increased demand. Deficiency in children can result in rickets, in adults it can contribute to high blood pressure and osteoporosis.

How can I get it?
Three portions of dairy per day, such as three slices of cheddar cheese, a yogurt and large glass of milk will provide your recommended daily allowance (RDA).

The best sources of calcium are dairy produce, small-boned fish such as sardines and anchovies, green leafy vegetables, nuts and seeds such as almonds and sesame seeds, tofu and apricots. You can also buy calcium-fortified bread, although it is much better to get it from natural sources.

Phosphorous

Phosphorous is one of the most essential minerals, playing a role in energy metabolism, calcium absorption and converting protein for growth, maintenance and repair of cells and tissues. It is readily available in most foods, including high protein foods.

How can I get it?
The main food sources are meat, milk and wholegrains, nuts and seeds.

Magnesium

Magnesium is an extremely important mineral and works to activate many enzymes, muscles and nervous functions. Symptoms of deficiency may include muscle cramps, headaches, loss of appetite, insomnia and a predisposition to stress.

How can I get it?
Magnesium occurs abundantly in whole foods and the best dietary sources are kelp, seaweeds, citrus fruits, green leafy vegetables such as broccoli, cabbage, nuts, wholegrains and tofu.

Chromium

Chromium is vital to the Glucose Tolerance Factor (GTF) - a critical enzyme system that works with insulin to absorb glucose into cells, regulating blood sugar levels. Chromium levels can be depleted by over-consuming refined sugars and white flour products and lack of exercise.

How can I get it?
The best sources are brewer's yeast, wholegrains, potatoes, apples, parsnips and bananas.

Iron

Iron is critical to human life. It plays the central role in the haemoglobin molecule of our red blood cells, where it works transporting oxygen from the lungs to the body's tissues and taking carbon dioxide from the tissues to the lungs. In addition, Iron functions in several key enzymes in energy production and metabolism including DNA synthesis. Iron deficiency is the most common deficiency worldwide and can lead to anaemia.

How can I get it?
A portion of red meat or sardines served with a dark green leafy vegetable such as kale will meet the RDA. Other good sources include offal, egg yolk and fortified cereals.

Selenium

Selenium works with vitamin E in preventing free radical damage to cell membranes. It is important for a healthy immune system, fertility and thyroid metabolism. It also helps to regulate blood pressure.

How can I get it?
A few Brazil nuts or a prawn sandwich made with wholemeal bread would provide the daily intake. Other good sources include offal, shellfish, butter, avocados and wholegrains.

Zinc

Zinc is part of more than 200 enzymes in our bodies. In fact, zinc functions in more reactions than any other mineral. Adequate zinc levels are needed for proper immune function and zinc deficiency results in an increased susceptibility to infection. It is essential for the maintenance of vision, taste and smell.

How can I get it?
Zinc is found in fish, shellfish, lean red meat, seeds, nuts, legumes and wholegrains.

Potassium

Potassium can help your muscles and nerves to function properly, lower your risk of high blood pressure and heart problems, ease fatigue, irritability and confusion. Older people are more at risk of too much potassium in the body as their kidneys are less able to eliminate excess.

How can I get it?
Potassium is found in many foods, and is especially easy to obtain in fruits and vegetables such as chard, mushrooms and spinach.

Sodium

Sodium is a component of salt, which is naturally present in the majority of foods we eat. Most people eat more salt than is good for their health. It is recommended that adults eat no more than 6g of salt (equivalent to 2.5g of sodium) per day. Three quarters of our salt consumption comes from packaged foods such as breakfast cereals, soups, sauces and ready meals.
 

Are you getting enough iron?

Spotlight on... high-iron

• By Jo Lewin - Associate nutritionist - Are you getting enough iron? Jo Lewin explains when you should eat a high-iron diet and which foods may help ensure you get your daily dose.

  

  Iron is an essential nutrient for growth and development and plays a critical role in transferring oxygen around the body. It constitutes a vital part of haemoglobin, the oxygen-carrying component of red blood cells. Haemoglobin is responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs. The mineral also plays a part in energy production, muscle function, DNA synthesis and the immune system. We get most of the iron we need from food and our body carefully monitors its levels of iron; absorbing more when demand is high and less when stores are adequate. Iron is stored primarily in the bone marrow and liver.

  The Recommended Daily Allowance (RDA) for iron is 8.7mg/day for men and postmenopausal women. For younger women it is 14.8mg per day, with an additional requirement recommended during pregnancy.

  Iron deficiency is surprisingly common in the UK and is particularly prevalent among infants under two, teenage girls, pregnant women and the elderly. According to government surveys, the majority of women do not reach their dietary target of 14.8mg.

  Iron deficiency

  Iron deficiency may be due to one or a combination of the following factors:

  • Blood loss. This is the most common cause of iron deficiency in women of childbearing age. This is most often due to excessive menstrual bleeding. Other causes of blood loss include bleeding from peptic ulcers, haemorrhoids and donating blood.
     
  • Increased iron requirement. Periods of growth during childhood and adolescence sharply increases the need for iron. The increased need for iron during pregnancymay not be met through diet alone and so supplementation may be advised to pregnant women as necessary. If you're pregnant and are concerned you may be deficient in iron please consult your doctor.
     
  • Inadequate dietary intake. This is also a common cause of deficiency. It is good to remember that plant-based sources of iron are a little harder for the body to absorb and that vitamin C will aid in absorption of all forms of iron. Typical infant diets, which are high in milk and cereals, can also be low in iron. Try a cereal fortified with iron to up intake.
     
  • Diminished iron absorption. This is often due to reduced gastric acid secretion in the stomach; such as atrophic gastritis (common in the elderly), chronic diarrhoea or prolonged use of antacids.

  Anaemia

  Periods of rapid growth such as adolescence, heavy bleeding, busy lifestyles and lack of iron in your diet will result in your body drawing on its iron reserve. Initially there are no symptoms, but as your iron supply dwindles, so does your body's ability to produce healthy red blood cells. The result is low numbers of red blood cells circulating the blood, a condition called iron-deficiency anaemia. Symptoms of anaemia include weakness, fatigue*, pale complexion, breathlessness, palpitations and an increased susceptibility to infection. Anaemic children have difficulty concentrating and may find it difficult to learn. Doctors can determine levels of body iron stores through a serum ferritin test.

  *A note on haemochromatosis...

  Haemochromatosis is a specific genetic disorder in which iron builds up over time, leading to excessive levels. If you have a family member with haemochromatosis, you should be screened to determine if you are at risk.

  It is hard to diagnose – but one of the symptoms is fatigue. If you are feeling very tired all the time, it is recommended that you go to your GP and have a blood test before embarking on iron supplementation.

  Read more about it at the NHS website.

  Supplements and safety

  Anaemia requires a careful diagnosis and treatment to correct the underlying cause. Consult a doctor before taking an iron supplement. When prescribed by a doctor, iron is typically taken in a form called ferrous salts - ferrous sulphate, ferrous fumerate or ferrous gluconate. Side effects of iron supplements may include constipation and stomach upsets so be cautious and do not exceed the recommended amount. Keep all supplements containing iron out of reach of children.
  

  Friends and foes

  It must be pointed out that there are two forms of iron. Haem iron is found in animal products and is the most efficiently absorbed form of iron. Non-haem iron is found in plant foods and the body finds it more difficult to absorb by comparison. Vitamin C is a strong promoter of iron absorption, and when vitamin C rich foods are combined with foods rich in iron, absorption of the iron is substantially increased. Watch the amount of tea you consume as a substance called tannins found in tea is thought to inhibit the absorption of iron. Be aware that decaffeinated teas contain just as much tannin as normal tea. Foods high in phytates and oxylates, such as spinach, nuts, chocolate, parsley and rhubarb may also have a negative impact on iron absorption so just make sure you try to eat a varied, balanced diet.
  
  

  Rich sources of iron

  Liver, beef & lamb	Soybeans
  Clams, mussels & oysters	Lentils
  Kidney beans	Tofu
  Leafy green vegetables	Blackstrapp molasses
  Dried figs & apricots	Quinoa
  Oatmeal, rye	Chickpeas
  Brewers yeast	Pinto beans