Why Calcium and Vitamin D 3 is so important for bones

Osteoporosis is known as a disease that manifests itself in childhood. Bone is removed and replaced throughout life, but during childhood, more bone is replaced than removed. This is why it is essential that all children reach their maximum peak bone mass. Peak bone mass is the highest amount of bone present in the human body, usually obtained by 25/30 years of age. 80% of a person’s bone is genetic and genetics also determine/contribute the amount of bone laid down.

Research has shown that 37% of girls and 28% of boys between the ages of 5-12, do not get the recommended daily amounts of calcium. In Ireland 74% of adults and 88% of primary school children, have less than half of the recommended daily amount of vitamin D.

Calcium and vitamin D3 are essential nutrients for the prevention and treatment of osteoporosis. Studies in senior citizens show that adequate calcium intake and vitamin D3 can lower the risk of fractures.

Substantial clinical evidence demonstrates that low calcium and vitamin D intake and/or poor absorption are linked to an increased risk of hip fractures in senior citizens. Many people are not aware of the devastating effects of a hip fracture and the fact that 90% of hip fractures are due to Osteoporosis.

·         20% of Irish people aged 60+ who fracture their hip will die within 6-12 months.

·         50% of Irish people aged 60+ who fracture their hip, will not be able to wash, dress or walk across a room unaided.

·         Only 30% of Irish people aged 60+ who fracture their hip will regain their independence. However once a person has fractured a hip, this places them at a higher risk of fracturing again.

·         1 hip fracture costs €55,000

·         One hip fracture occurs every 30 seconds in the EU


Calcium is the most common mineral found in our bones and helps to give them strength and rigidity. Calcium is also particularly important at the time of menopause, because calcium absorption slows down, due to low levels of oestrogen.

A deficiency in Calcium can cause bones to become brittle on the inside and therefore they break very easily. On the outside a person looks perfectly fine. Every cell in our body, including those in the heart, nerves and muscles rely on calcium. Calcium is also necessary for your body to form blood clots.

Calcium alone is not enough to treat bone loss and is not a substitute for drug therapies that treat bone loss. It is essential that calcium is taken in conjunction with Vitamin D3, no one should just be taking calcium.

The richest sources of calcium in food are milk, yoghurt and cheese. Calcium is more easily absorbed through daily products, versus non-dairy.

Calcium sources

The best sources of calcium from food are milk, yoghurt and cheese. Bread, nuts and any oily fish (e.g. sardines and tuna) also contain calcium, as well as some dark green vegetables. Some brands of orange juice and most breakfast cereals have calcium.

The servings below each contain between 200-230mg of calcium. Pregnant women and teenagers require 1200mg/day of calcium and will need at least 5 of these servings to get the recommended daily intake. Three servings are recommended for adults and children.

·         A yoghurt contains between 200-230 mg of calcium.

·         A glass of fortified milk

·         A  matchbox size of cheese

* All product labels should be checked as amounts vary.

Combine the above with thirty minutes of appropriate weight bearing exercise for adults (sixty minutes for children/teenagers) and the daily amounts of vitamin D, to help prevent and treat osteoporosis.

How much Calcium do you need?

0-12 months = 525 (non breast fed infants only)*

1-3 years = 500 mg per day***

4-8 years = 800 mg per day**

9-18 years = 1300 mg per day**

Pregnant/or breastfeeding women 18 years & under = 1300 mg per day**

Women 19-49 years = 1000 mg per day**

Pregnant and breastfeeding women 19 years + = 1000 mg per day**

Women 50+ years = 1200 mg per day**

Men 19-49 years = 1000 mg per day**

Men 50+ years = 1200 mg per day**

*Teenagers & pregnant/breastfeeding mothers may need to increase to 1500mg calcium per day if they have Osteopenia and/or Osteoporosis.


* National Osteoporosis Society UK

** National Osteoporosis Foundation USA

*** IOF-FAO/WHO: Human Vitamin and Mineral Requirements

Vitamin D3

Vitamin D3 is an essential part of preventing and treating Osteoporosis. Vitamin D3 is essential for the absorption of calcium, it increases the body’s ability to absorb calcium by 30-80%. Without Vitamin D3, calcium will not be as easily absorbed by your body, which could affect the formation of healthy bones and teeth. Vitamin D3 also helps to regulates cell growth and the immune system.

Vitamin D3 is often referred to as the “sunshine vitamin”. When a person’s skin is exposed to ultraviolet B rays, the skin makes vitamin D. Vitamin D is a fat-soluble vitamin that when consumed or made in the skin, can be stored in the blood and body fat, for several months.

Approximately 10-15 minutes of sunlight a day (depending on skin type), on any part of your body (arms, legs, etc…) during the summer months will enable the body to store vitamin D3. If you are very light-skinned, 2-3 minutes for approximately 4-5 times during the day. However, it is very important to avoid over-exposure resulting in sunburn, as we are all aware of the damaging effects of the sun, especially in terms of skin cancer. Wearing sunblock, makeup and/or moisturizers with sunblock in them continuously, will inhibit vitamin D3 absorption also wearing burkas for religious reasons.

Due to Ireland’s northerly latitude, very little UV light is available between October and March, which can result in low levels of Vitamin D. The Vitamin D that we store in the summer months has to last through the winter season.

NOTE: We have not had much sun in the summer for years; therefore, vitamin D levels usually are not met in our “summer” months. This is why it so important for people to get vitamin D from other sources.

Rickets is a severe vitamin D deficiency and babies are being born in Ireland with this preventable condition. Research has shown that there is a worldwide epidemic of low vitamin D levels, especially in infants, children, adolescents, pregnant women and senior citizens.

What happens if we take too much Vitamin D

An increasing number of people appear to be taking far too much vitamin D. Excessive vitamin D intake can build up and reach toxic levels in the body. This outcome happens when a person accidentally consumes too much vitamin D, by taking vitamin D from both food and supplements.

If vitamin D intake is excessive, blood calcium may reach levels that cause symptoms that are not only unpleasant but dangerous. However, these symptoms do not occur in everyone with elevated calcium levels. Stomach pain, constipation and diarrhoea are common digestive complaints that can be related to food intolerances or irritable bowel syndrome. However, they also can be a sign of elevated calcium levels, caused by vitamin D intoxication.

Too much vitamin D may lead to kidney injury in people with healthy kidneys, as well as in those with established kidney disease. However, they also can be a sign of elevated calcium levels, caused by high levels of vitamin D.

NOTE: If you are in the sun and taking vitamin D through food or supplements, then you need to use the highest sunblock factor. Using sunblock helps to prevent high vitamin D levels. Consider reducing your vitamin D intake from food/supplement while in the sun.

The efficacy of prescription osteoporosis treatments is maximized by osteoporosis patients getting the daily recommended amounts of calcium and vitamin D3.

A growing number of human metabolic, epidemiologic, and animal studies are indicating that low levels of Vitamin D, appear to be linked to the following conditions:

·         Immune function diseases such as: Type 1 diabetes, multiple sclerosis and rheumatoid arthritis, but further research is required to prove/understand these links.

·         Some cancers (breast, colon and prostate) but further research is required to prove/understand these links.

·          Low levels of Vitamin D have been linked with TB and osteomalacia in adults.

·         A Vitamin D deficiency is thought to mimic the aches and pain symptoms of fibromyalgia.


Who is at risk of low vitamin D levels?

·         Babies who are just fed breast milk, consume little vitamin D3, especially if the mother is vitamin D3 deficient.

·         Senior citizen’s: Their ability to produce vitamin D3 in their skin from the sun, is reduced with age and they are less able to convert it into the Vitamin D hormone that the body needs.

·         Those who continuously wear sun block, moisturisers or make up that have sun block in them.

·         People who are obese as body fat has a tendency to hold onto vitamin D, so reducing its overall availability to the rest of the body.

·         Those with darker skin (e.g. Africans) do not absorb vitamin D3 from the sun, as easily as lighter skinned people.

·         Those who have: gastrointestinal disorders such as Coeliac Disease (Gluten/wheat sensitivity); Crohn’s and Ulcerative Colitis; or Primary Biliary cirrhosis.

·         Those, who do not get the recommended daily amounts of Vitamin D3 from the sun or through food sources.

Vitamin D3 can be found in some foods:

·         Yogurts (for example: Calin +)

·         Fortified milks (Avonmore)

·         Oily fish

·         Eggs

·         Chicken livers

·         Breakfast cereals

Please check individual labels for vitamin D amounts as they can vary and not all yogurts and breakfast cereals have vitamin D.

How much do you need?

Babies 0-12 months breast fed or formula fed = 5µ/200 IU *

Children 1-18 years= 10µ/400 IU per day***

Adult women 19-49 years = 10-20µ/400-800 IU per day**

Adult women 50+ years = 20-30µ/800-1000 IU per day**

19+ years pregnant and/or breastfeeding = 20-30µ/800-1000 IU per day**

Adult men 19-49 years =10-20µ/400-800 IU per day**

Adult men 50+ years =20-30µ/800-1000 IU per day**


* HSE 2011

** National Osteoporosis Foundation USA

*** American Academy of Paediatrics.


Remember also to take plenty of fresh fruit and vegetables that contain other vitamins and minerals.


Calcium and Vitamin D3 supplements

There may be inadequate amounts of Calcium and Vitamin D3 in the diet, and supplementation is necessary when dietary intake of Calcium and especially vitamin D3 is inadequate.

Vitamin D supplements:

To avoid constipation problems while taking calcium supplements, make sure to take plenty of fluids throughout the day (2 litres is recommended, preferably water). Always consult your Doctor before taking any new medication, supplement or increased fluid intake.

The following can help a child reach their peak bone mass, which can reduce their risk of developing Osteoporosis in later life:

·         Daily recommended amounts of calcium and vitamin D3

·         Adequate calories, including protein

·         Weight bearing exercise/physical activity for a minimum of one hour a day

·         Eating disorders: A DXA scan done ASAP and seek medical advice

·         Check with the Childs physician, if they are taking any medication or have a condition that can cause bone loss. Examples: Chemotherapy, steroids and asthma.

The following can help an adult reduce their risk of developing Osteoporosis:

·         Daily recommended amounts of calcium and vitamin D3

·         Adequate calories, including protein

·         Weight bearing exercise/physical activity for a minimum of thirty minutes a day

·         Eating disorders: A DXA scan done ASAP and seek medical advice

Check with your physician if you are taking any medication or have a condition that can cause bone loss. Examples: Arimidex, Warfarin, currently going through the menopause, Depo Provera, Crohn’s disease. For full list of risk factors, please check our risk factor list.