… and vice versa!
Many people take medicines: daily, sometimes even several times a day and often for a longer period of time. Taking medicines on a daily basis sometimes affects the absorption of vitamins. This also applies the other way around, vitamins sometimes influence the effect of a medicine.
The Vitamin Information Bureau lists the most important interactions (interactions) between vitamins and medicines. In general, however, the following always applies: check the package leaflet of the medicine you are taking and consult with your doctor.
Vitamin K and Anticoagulant Drugs
Thrombosis is a condition in which the blood actually clots too well: a blood clot spontaneously forms in the blood vessels. This is dangerous, because a clot can cut off the blood supply to organs and tissues. That is why oral anticoagulation is prescribed for thrombosis (acenocoumaroll or phenprocoumon).
Vitamin K is important for blood clotting. It helps in the production of clotting factors. The classic anticoagulants (coumarins) counteract vitamin K. As a result, fewer clotting factors are produced, so that the blood clots less quickly and the risk of thrombosis decreases. A large amount of vitamin K may reduce the effectiveness of the anticoagulant. Ideally, there is a balance between the action of the anticoagulant drugs and that of vitamin K. Increasingly, so-called direct oral anticoagulants (DOACs) are prescribed. The interaction with vitamin K does not play a role here.
Nutrition and vitamin K
Eating vitamin K-rich vegetables is not a problem. Only ten to thirty percent of the vitamin K from this is absorbed into the body. It is important to eat a varied diet and not to choose vegetables that are rich in vitamin K every day. These are mainly green leafy vegetables such as kale and spinach.
Vitamin K . Supplements
A large amount of vitamin K may reduce the effectiveness of the anticoagulant. If a supplement contains less than 100 micrograms of vitamin K (125 percent RDA), this effect will not occur. Ideally, there is a balance between the action of the anticoagulant drugs and that of vitamin K (in food and supplements). The thrombosis service and/or a dietician can advise on this.
Diabetes drugs and vitamin B12
Bee diabetes (diabetes) the body can no longer regulate blood sugar. This is done very accurately in healthy people, with the hormone insulin. Normally, insulin is produced by cells in the pancreas, the so-called islets of Langerhans. In people with type 1 diabetes, these cells are destroyed by their own immune system. The pancreas no longer produces insulin.
In type 2 diabetes, the insulin works less well and the body also makes less and less insulin. Not enough glucose is then removed from the blood. In addition, fat metabolism and blood pressure are often disrupted. Type 2 diabetes is usually treated with medication, plus dietary and exercise advice. About 85 percent of people with diabetes have this form.
One of the drugs prescribed for type 2 diabetes (metformin) may contain a vitamin B12 deficiency cause. Recent research shows a 19 percent decrease in vitamin B12 levels in the blood when using this drug.
The deficiency of vitamin B12 is caused by the diabetes drug metformin, which reduces the absorption of vitamin B12 in the intestines. The complaints caused by a vitamin B12 deficiency are quite general in nature and are common.
But when a deficiency of vitamin B12 is the culprit, the complaints can be prevented and treated. According to the researchers, it may be useful if diabetic patients taking metformin have their vitamin B12 level checked regularly by their GP. And the GP should in any case consider a possible vitamin B12 deficiency due to metformin if patients have complaints that fit in with that picture. It is also possible to take a vitamin B12 supplement preventively, in consultation with your doctor.
Statins (cholesterol lowering drugs) and vitamin D
Statins lower cholesterol levels in the body by inhibiting the production of cholesterol in the liver. The Dutch Journal of Medicine recently published an article in which it was reported about the underestimation of muscle complaints caused by the use of statins (cholesterol lowering agents).
Around 10 percent of statin users appear to suffer from muscle complaints. Frequently reported complaints are muscle pain in the upper arms, thighs, thighs, calves and back. Sore tendons, nighttime muscle cramps, fatigue and muscle weakness are also common. Recent American research shows that a lack of vitamin D in the blood is associated with these complaints.
People who use statins and who have muscle complaints were also found to have too little vitamin D in the body. When the patients were given extra vitamin D, the complaints disappeared in 92 percent of them. The doctor can determine the vitamin D value in the blood.
Other interactions
More interactions are known. An example is the influence of diuretics (water tablets) on the absorption of B vitamins. Calcium (from food or from supplements) can interact with certain medications (for example, antibiotics and thyroid medications).
Such interactions are described in the diagram below.
| Influence on: | |
| Vitamin K | Anticoagulants |
| Statins (cholesterol lowering drugs) | Vitamin D absorption |
| Metformin (diabetes drug) | Vitamin B12 absorption |
| Calcium (from food or supplements) | Certain antibiotics Medicines against osteoporosis iron tablets Thyroid drugs Digoxin (against heart rhythm disorders) |
| Diuretics (water tablets) | Absorption of B vitamins |
| grapefruit juice | Statins Resources for the heart Sleeping aids (alprazolam, midazolam) Hay fever remedy (terfenadine) |
If you take medicines and a vitamin supplement, it is always wise to consult with your doctor about the use of these.
Would you like to know more about vitamins and minerals? Then look at www.vitamine-info.nl.
Sources:
1. Schurgers LJ et al. Effect of vitamin K intake on the stability of oral anticoagulant treatment: dose response relationships in healthy subjects. Blood First Edition Paper, prepublished online July 1, 2004; DOI 10.1182/blood-2004-04-1525
2. Ahmed W., Khan N., Glueck CJ et al. (2009). Low serum 25 (OH) vitamin D levels (<32 ng/mL) are associated with reversible myositis-myalgia in statin-treated patients. transl. res. 153:11-16.
3. Janssen SP, Smulders YM, Gerdes VE et al. (2010). Muscle complaints due to statins: underestimated. Ned. timetable cured. 154: 1421-1425.
4. Scientific state of affairs with regard to vitamins, minerals and trace elements, TNO Nutrition, 2007
5. Medicines 1+1 is sometimes 100, Gezondgids mei 2009.
6. www.trombose.nl
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